ICHTHYOLOGY [CLASSIFICATION. head ; gill-openings very wide, the gill-membranes not being united. Genera: Ammodytcs (Sand-Eels) and Bleekeria. 5. Congrogadina : No ventral fins whatever ; vent remote from the head ; gill-openings of moderate width, the gill-membranes being united below the throat, not attached to the isthmus. Genera : Congrogadus and Haliophis. Family 4. Macruridcs. Body terminating in a long, compressed, tapering tail, covered with spiny, keeled, or striated scales. One short anterior dorsal ; the second very long, continued to the end of the tail, and composed of very feeble rays ; anal of an extent similar to that of the -second dorsal; no caudal. Ventral fins tho racic or jugular, composed of several rays. Deep-sea Gadoids. Genera: Macrurus, Coryphcenuides, Macruronus, Malacocephalus, and Bathygadus. DIVISION II. Anacanthini Pleuronectoidei. Head and part of the body unsymmetrically formed. This division consists of one family only: Pleuronectldie (Fiat-Fishes). Genera : Psettodes, Hippoglossus (Holibut), Hippoglossoides, Tc- phritis, Rhombus (Turbot, Brill, Whiff), Phrynorhombus (Top- Knot), Arnoglossus, Pseudorhombus, Rhomboidichthys, Citharus, Antidtharus, Brachyplcura, Samaris, Pscttichthys, Citharichthys, Hemirhombus, Paralichthys., Liopsctta, Lophonectes, Lepidopsetta, Thysanopsettit, Pleuronedes (Plaice, Dab, Flounder), Ehombosolea, Parophrys, Psammodiscus, Ammotretis, Peltorhamphus, Nematops, Lceops, Pcecilopsetta, Solea (Sole), Synaptura, JEsopia, Gymnachirus, Cynoglossus, Soleoialpa, Apionichthys, Ammopleurops, Aplwristia, and Plagusia ORDER IV. Physoslomi. All the fin-rays articulated, only the first of the dorsal and pec toral fins is sometimes ossified. Ventral fins, if present, abdominal, without spine. Air-bladder, if present, with a pneumatic duct (except in Scombresocidas). Family 1. Siluridce. Skin naked or with osseous scutes, but without scales. Barbels always present; maxillary bone rudimen tary, almost always forming a support to a maxillary barbel. Mar gin of the upper jaw formed by the intermaxillaries only. Sub- operculum absent. Air-bladder generally present, communicating with the organ of hearing by means of the auditory ossicles. Adi pose fin present or absent. A large family of freshwater fishes, represented by numerous genera, which exhibit a great variety of form and structure of the fins. Their first appearance is indicated by some fossil remains in Tertiary deposits of the highlands of Fadang in Sumatra, where Pscudeutropius and Sagarins, types well represented in the living Indian fauna, have been found. In North America also spines referable to " Cat-Fishes " have been found in Tertiary formations. From the great number of different generic types this family has 6een arranged under eight subdivisions : 1. Siluridce Homalopterce. A. Olariina, : Clarias, Heterobranchus. B. Plotosina : Flotosus, Cnidoglanis, Copidoglanis, Chaca. 2. Siluridoe Heteropterce. A. Silurina : Saccobranchus, Silurus, Schilbe, Eutropius, Silurichthys, "Wallago, Belodontichthys, Eutropiichthys, Cryptopterus, Callichrous, Hemisilurus, Siluranodon, Ailia, Schilbichthys, Lais, Pseudeutropius, Pangasius, Helicophagus, Silondia. 3. Siluridoe Anomalopterce. A. Hypophthalmina : Hypophthalmus, Helogenes. 4. Siluridce Proteropterce. A. Bagrinn : Bagrus, Chrysichthys, Clarotes, Macrones, Pseudobagrus, Liocassis, Bagroi des, Bagrichthys, Rita, Acroehordonichthys, Akysis. B. Amiurina : Amiurus, Hopladelus, Noturus. C. Pimelodina : Platystoma, Sorubim, Hemisorubim, Platystomatichtliys, Phractocephalus, Piramutana, Platy- nematichthys, Piratinga, Bagropsis, Sciades, Pimelodus, Pirinampus, Conorhynchus, Notoglanis, Callophysus, Lophiosilurus, Auchenoglanis. D. Ariina: Arius, Galeichthys, Genidens, Paradiplomystax, Diplomystax, ^Elurichthys, Hemipimelodus, Ketengus, Osteogeniosus, Batrachocephalus, Atopochilus. E. Bayariina; Bagarius, Englyptosternum, Glyptosternum. 5. Siluridce Stcnobranchice. A. Doradina : Ageniosus, Tetranematichthys, Euaneinux, Auchenipterus, Glanidium, Centromochlus, Trachelyo- pterus, Cetopsis, Astrophysus, Doras, Synodontis. B. Rhinoylomina : Rhinoglanis, Callonwstax. C. Mulapterurina; Malapterurus. 6. Siluridce Proteropodcs. A. Ilypostomatina : Stygogenes, Arges, Brontes, Aslroplc- bus, Callichthys, Cluetostomus, Plecostomus, Hypopto- poma, Loricaria, Acestra, Sisor, Erethistes, Exostoma, Pseudecheneis. B. Aspredinina : Aspredo, Bunoccphalus, Bunocephal- ichthys, Harltia. 7. Siluridce Opisthoptcrce. A. Nematogenylnn: Heptapterus, Nematogenys. B. Trichomycterina: Trichomycterus, Eremophilus, Pari- odon. 8. Siluridcv Branchicoloe : Stegophilus, Vandellia. Family 2. Scopdidce. Body naked or scaly. Margin of the upper jaw formed by the intermaxillary only ; opercular apparatus sometimes incompletely developed. Barbels none. Gill-opening very wide ; pseudobranchi;e well developed. Air-bladder none. Adipose fin present. The eggs are enel jsed in the sacs of the ovary, and excluded by oviducts. Pyloric appendages few in number or absent. Intestinal tract very short. Genera : Saurus, Bathysaurus, Bathypterois, Harpodon, Scopelus, Ipnops, Paralepis, Sudis, Plagyodus, Aulopus, Chlorophthalmus, Scopclosaurus, Odontostomus, and Nannobrachium. Fossil : Osme- roidcs, Hemisaurida, Parascopelus, and Anapterus. Family 3. Cyprinidcc. Body generally covered with scales; head naked. Margin of the upper jaw formed by the intermaxil laries. Belly rounded, or, if trenchant, without ossifications. No adipose fin. Stomach without blind sac. Pyloric appendages none. Mouth toothless ; lower pharyngeal bones well developed, falciform, subparallel to the branchial arches, provided with teeth, which are arranged in one, two, or three series. Air-bladder large, divided into an anterior and posterior portion by a constriction, or intoa rightor a left portion, enclosed in an osseous capsule. Ovarian sacs closed. The family of " Carps " is the one most numerously represented in the fresh waters of the Old World and of North America. Numerous fossil remains are also found in Tertiary freshwater formations ; the majority can be referred to existing genera : Barbus, Thynn- ichthys, Gobio, Lcuciscus, Tinea, Amblypharyngodon, Rhodeus, Cobitis, Acanthopsis ; only a few showing characters different from those of living genera : Cyclurus, Hcxapsephus, Mylocyprinus. There is much less diversity of forms and habits in this family than in the Siluroids ; but the genera are sufficiently numerous to demand a further subdivision "f the family into groups. 1. Catostomina : Catostomus, Moxostoma, Sclerognatlms, Car- piodes. 2. Cyprinina : Cyprinus (Carp), Carassius, Catla, Cirrhina, Dangila, Osteochilus, Labeo, Barynotus, Tylognathus, Abrostomus, Discognathus, Crossochilus, Gymnostomus, Epalzeorhynehus, Capoeta, Barbus (Barbel), Thynnichthys, Barbichthys, Ambly- rhynchichthys, Albulichthys, Oreinus, Schizothorax, Ptychobarbus, Gymnocypris, Schizopygopsis, Diptychus, Aulopyge, Gobio (Gud geon), Ceratichthys, Bungia, Pimephales, Hyborhyuchus, Cam- postoma, Hybognathus, Ericymba, 1 seudorasbora, Cochlognathus, Exoglossum, Rhinichthys. 3. Rhotcichtliyina : Rhoteichthys. 4. LcptobarUna : Leptobarbus. 5. Rasborina : Rasbora, Luciosoma, NiU ia, Aphyocypris, Ambly pharyngodon. 6. Scmiplotina : Cyprinion, Semiplotus. 7. Xenocypridina : Xenocypris, Paracanthobrama, Mystaco- leucus. 8. Leudscina: Leuciscus (White-Fish, Roach, Chub, Dace, Rudd, Minnow), Myloleucus, Ctenopharyngodon, Mylopharodon, Para- phoxinus, Meda, Graodus, Tinea (Tench), Leucosomus, Chondro- stoma, Orthodon, Acrochilus. 9. Rhodeina : Achilognathus, Rhodeus, Pseudoperilampus. 10. Danionina: Danio, Pteropsarion, Aspidoparin, Barilius, Boln, Schacra, Opsariichthys, Squaliobarbus, Ochetobius. 11. Hypophtlialmichtliyina : Hypophthalmichthys. 12. Abramidina : Abramis (Bream), Aspius, Alburnus (Bleak), Leucaspius, Rasborichthys, Elopichthys, Pelotro})hus, Acantho- brama, Osteobrama, Chanodichthys, Smiliogastcr, Culter, Pelecus, Eustira, Chela, Pseudolabuca, Cachius. 13. ffomalopterina : Homaloptera, Psilorhynchus. 14. Cobitidina (Loaches) : Misgurnus, Nemachilus, Cobitis, Lcpidocephalichthys, Acanthopsis, Botia, Oreonectes, Lepido- cephalus, Acanthophthalmus, Apua, Paramisgurnus. Family 4. Kneriidce. Body scaly, head naked. Mai-gin of the upper jaw formed by the intermaxillaries. Dorsal and anal fins short, the former belonging to the abdominal portion of the vertehnd column. Teeth none, either in the mouth or pharynx. Barbels none. Stomach siphonal; no pyloric appendages. Pseudobranchise none. Branchiostegals three ; air-bladder long, not divided. Ovaries closed. One genus : Kncria. Family o. Charadnidce. Body covered with scales, head naked ; barbels none. Margin of the upper jaw formed by the intermaxil laries in the middle and by the maxillaries laterally. Generally a small adipose fin behind the dorsal. Pyloric appendages more or Kiss numerous ; air-bladder transversely divided into two portions, and communicating with the organ of hearing by means of the auditory ossicles. Pseud obranchise none. 1. Erythrinina : Macrodon, Erythrinus, Lebiasina, Naunostomus,
Pyrrhulina, and Corynopoma.
