CLASSIFICATION.] Eye lateral, large or of moderate size. Gill-openings wide. Verte brae very numerous. Genera: Athcrina, Atherinichthys, and Tctragonurus. Family 3. Mugilidce (Grey Mullets). Body more or less oblong and compressed, covered with cycloid scales of moderate size; lateral line none. Cleft of the mouth narrow or of moderate width, with or without feeble teeth. Eye lateral, of moderate size. Gill-open ing wide. The anterior dorsal tin composed of four stiff spines. Vertebra? twenty-four. Genera : Mugil, Agonostoma, and Myxus. DIVISION XII. Acanthopterygii Gastrosteiformes . The spinous dorsal is composed of isolated spines, if present ; the ventrals are either thoracic or have an abdominal position in consequence of the prolongation of the pubic bones which are attached to the humeral arch. Mouth small, at the end of the snout, which is generally mure or less produced. Family 1. Gastrostcidce. Body elongate, compressed. Cleft of the mouth oblique ; villiform teeth in the jaws. Opercular bones not armed ; infraorbitals covering the cheek ; parts of the skeleton forming incomplete external mail. Scales none, but generally large scutes along the side. Isolated spines in front of the soft dorsal tin. Ventral tins abdominal, joined to the pubic bone, com posed of a spine and a small ray. Branehiostegals three. One genus only : Gastrosteus (Sticklebacks). Family 2. Fixtulariidcc. Fishes of greatly elongated form ; the anterior bones of the skull are much produced, and form a long tube, terminating in a narrow mouth. Teeth small ; scales none, or small. The spinous dorsal fin is either formed by feeble isolated spines or entirely absent ; the soft dorsal and anal of moderate length ; ventral fins thoracic or abdominal, composed of five or six rays, with out spine; if abdominal, they are separate from the pubic bones, which remain attached to the humeral arch. Branchiostegals five. Genera: Fistularia, Aulostoma, Auliscops, and Aulorhynchus. The first three occur also in Eocene formations. Other fossil genera .are Urosphen and Ehamphosus, DIVISION XIII. Acanthopterygii Ccntrisciform.es. Two dorsal fins ; the spinous short, the soft and the anal of moderate extent. Ventral fins truly abdominal, imperfectly developed. One family, Gentriscidce, with two genera, Centriscus (Trumpet- Fish, Bellows-Fish) and Amphisile. DIVISION XIV. Acanthopterygii Gobicsociformcs. No spinous dorsal ; the soft and the anal short or of moderate length, situated on the tail ; ventral fins subjugular, with an adhesive apparatus between them. Body naked. Genera : Chorisochismus, Cotylis, Sicyascs, Gobicsox, Diplocrepis, Crepidogaster , Trachelochismus, Lepadogaster, and Leptopterygius. DIVISION XV. Acanlhoptcrygii Channiformes. Body elongate, covered with scales of moderate size ; no spine in any of the fins ; dorsal and anal long. No superbranchial organ, only a bony pro minence on the anterior surface of the hyomandibular. Genera : Ophioccphalus and Channa. DIVISION XVI. Acanthopterygii Labyrinthibrancliii. Body com pressed, oblong or elevated, with scales of moderate size. A superbranchial organ in a cavity accessory to that of the gills. Family 1. Labyrinthici. Dorsal and anal spines present, but in variable number ; ventrals thoracic. Lateral line absent, or more or less distinctly interrupted. Gill-opening rather narrow, the gill-membranes of both sides coalcscent below the isthmus, and scaly ; gills four ; pseudobranchise rudimentary or absent. Genera : Anabas, Spirobranckus, Ctenopoma, Poly acanthus, (Paradise-Fish), Osphronicnus (Goramy), Trichogaster, Betta, and Micr acanthus. Allied to this family is Luciocephalus. DIVISION XVII. Acanthopterygii Lophotiformes. Body ribbon- shaped, with the vent near its extremity ; a short anal behind the vent ; dorsal fin as long as the body. Only one genus is known of this division or family, Lopliotes. DIVISION XVIII. Acanthopterygii Tccniiformes (Ribbon-Fishes). Body ribbon-shaped; dorsal fin as long as the body; anal absent; caudal rudimentary, or not in the longitudinal axis of the fish. Genera : Trachyptcrus, Stylophorus, and Regalecus. DIVISION XIX. Acanthopterygii Notacanthiformcs.Dor$& fin short, composed of short, isolated spines, without a soft portion. Anal fin very long, anteriorly with many spines; ventrals abdo minal, with more than five soft and several unarticulated rays. One genus only : Notacanthus. ORDER II. Acanthopterygii Pharyngognathi. Part of the rays of the dorsal, anal, and ventral fins are non- articulated spines. The lower pharyngcals coalesced. Air-bladder without pneumatic duct. Family 1. Pomaccntridcc. Body short, compressed, covered with ctenoid scales. Dentition feeble ; palate smooth. The lateral line does not extent] to the caudal fin, or is interrupted. One dorsal fin, with the spinous portion as well developed as the soft, or more. Two, sometimes three, anal spines ; the soft anal similar to the soft dorsal. Ventral fins thoracic, with one spine and five soft 091 rays. Gills three and a half; pseudobranchiffl and air-bladder present. Vertebrae, twelve abdominal and fourteen caudal. Genera : Amphiprion, Premnas, Dascyllus, Lepidozygus, Pom- accntrus, Glyplddodon, Parma, and Heliastes. Fossil : Odontcus. Family 2. LabridcK. Body oblong or elongate, covered with cycloid scales. The lateral line extends to the caudal, or is in- terrupted. One dorsal fin, with the spinous portion as well developed as the soft, or more so. The soft anal similar to the soft dorsal. Ventral fins thoracic, with one spine and five soft rays. Palate without teeth. Branchiostegals five or six ; gills three and a half ; pseudobranchire and air-bladder present. Pyloric appendages none ; stomach without csecal sac. Genera : Labrus and Crenilabrus (Wrasses), Tauloga, Ctenolabrus, Acantholabrus, Centrolabrus, Lachnolcemus, Malacopterus,Gossyphus, Chilinm, Epibulus, Ananases, Platyglossus, Novacula, Julis, Coris, Cluerops, Xiphochilus, Semicossyphus, Trochocopus, Dccodon, Ptcr- agogus, Clepticus, Labrichtliys, Labroides, Duymcvria, Cirrhilabrus, Doratonotus, PseudochiHnus, Hemigymnus, Gomphosus, Chtilio, Cymolutes, Pseudodax, Scants, Scarichthys, Callyodon, Pseudo- scarus, Odax, Coridodax, Olistherops, and Siphonognathus. Fossil : Nummopalatus, Phyllodus, Taurinichthys, and Egertonia. Family 3. Embiotocidce. Body compressed, elevated or oblong, covered with cycloid scales ; lateral line continuous. One dorsal fin, with a spinous portion, and with a scaly sheath along the base, which is separated by a groove from the other scales ; anal with three spines and numerous rays ; ventral fin thoracic, with one spine and five rays. Small teeth in the jaws, none on the palate. Pseudobranchue present. Stomach siphonal ; pyloric appendages none. Viviparous. Genera : Ditrema and Hysterocarpus. Family 4. Chromides. Body elevated, oblong or elongate, scaly, the scales being generally ctenoid. Lateral line interrupted or nearly so. One dorsal fin, with a spinous portion ; three or more anal spines ; the soft anal similar to the soft dorsal. Ventral fins thoracic, with one spine and five rays. Teeth in the jaws small, palate smooth. Pseudobranchiae none. Stomach csecal ; pyloric appendages none. Genera : Etroplus, Chromis, Hcmichromis, Parctroplus, Acara, Heros, Neetroplus, Mesonauta, Petcnia, Uaru, Hygrogonus, Cichln, Crenicichla, Chcetobranchus, Mesops, Satanoperca, Geophagus, Sym- physodon, and Ptcrophyllum. ORDER III. Anacanthini. Vertical and ventral fins without spinous rays. The ventral fins, if present, are jugular or thoracic. Air-bladder, if present, without pneumatic duct. DIVISION I. Anacanthini Gadoidei. Head and body symmetric ally formed. Family 1. Lycodidce. Vertical fins confluent. Ventral fin, if present, small, attached to the humeral arch, jugular. Gill-opening narrow, the gill-membrane being attached to the isthmus. Genera : Lycodes, Gymnelis, Uroncctes, Microdcsmus, Blcn- nodcsmus, and Maynca. Family 2. Gadidce. Body more or less elongate, covered with small smooth scales. One, two, or three dorsal fins, occupying nearly the whole of the back ; rays of the posterior dor.sal well developed ; one or two anal fins. Caudal free from dorsal and anal, or, if they are united, the dorsal with a separate anterior portion. Ventrals jugular, composed of several rays, or, if they are reduced to a filament, the dorsal is divided into two. Gill- opening wide ; the gill-membranes generally not attached to the isthmus. Pseudobrancliiaj none, or glandular, rudimentary. An air-bladder and pyloric appendages generally present. Genera : Gadus (Cod-Fish, Haddock, Whiting, Pollack, Coal- Fish), Gadiculus, Mora, Strinsia, Halargyreus, Mclanonus, Mcrluccius (Hake), Pseudophyris, Lotella, Physiculus, Uraleptus, Lccmoncma, Phycis, Haloporphyrus, Lota (Burbot), Molva (Ling), MoteUa (Rockling), Ranicc/is, Bregmaccros, Muramolepi.i, Chiasmodus, and Brosmius. Fossil remains are rare: Ncmoptcryx and Palccogadi s from the schists of Glarus, a formation believed to have been the bottom of a very deep sea. In the clay of Sheppey species occur allied to Gadus, Mcrluccius, and Phycis. Family 3. Ophidiidcc. Body more or less elongate, naked or scaly. Vertical fins generally united ; no separate anterior dorsal or anal; dorsal occupying the greater portion of the back. Ventral fins rudimentary or absent, jugular. Gill-openings wide, the gill-mem branes not attached to the isthmus. 1. Brotulina: Ventral fins present, attached to the humeral arch. Genera : Brotula, Lucifuga, Bathyncctcs, Acanthonus, TypJilonus, Aphyonus, llltinonus, Sirembo, Ptcridium, Brotuloplds, Halidcsmus, Dincmatichthijs, and Bytldt.es. 2. Ophidiina: Ventral fins replaced by a pair of bifid filaments (barbels) inserted below the glossohyal. Genera : Ophidinm ai;d Gcnypterus. 3. Ficrasfcrina : No ventral fins whatever ; vent at the throat. Genera: Ficrasfcr and Enchcliophis.
4. Ammodytina: No ventral fins whatever ; vent remote from the
