A HISTORY OF SUFFOLK borrowed plumes and scraps of clothing they seek to efface themselves. Not only do they allow weeds and sponges and other zoophytes to grow upon their carapaces, but of their own accord carefully aiBx them. What thus they don, they can also at their pleasure doff. To this tribe, in the family Inachidae, belongs the species Macropodia rostrata (Linn.), which Mr. Claude Morley in 1893 observed in the Ipswich Museum, the place of capture being recorded as South- wold. Mr. Morley laments that at a later date the record of locality had been removed from most of the crustacean specimens in this museum. The nearly related species M. tenuirostris (Leach) is reported by Metzger^ as taken by the Pommerania in 23 fathoms depth, south-east of Yarmouth. In the same tribe Hyas araneus (Linn.), of the family Hyadidae, is recorded by Mr. Morley as brought in by Southwold fishing-boats, and it may be added that in May 1907 a dead specimen was picked up on the north beach at Lowestoft. Among the characters which serve to distin- guish these species one from another, it may be noted that in the genus Hyas the tail-part or pleon is divided into seven segments, a number never exceeded in any malacostracan pleon, though it is often enough apparently not attained. In Macropodia the number is only six, owing not to any real loss of a segment, but to a coalescence which has taken place between the sixth and the seventh. In this genus also the eyes have no proper orbits, but are salient and non-retractile, whereas in Hyai there is a cup-like hinder portion of the orbit into which the eye can be deflexed. Between M. rostrata and M. tenuirostris one mark of difference is that the two closely adjacent arms of the rostrum in the former are shorter, and in the latter species longer, than the peduncles of the second antennae. In both the rostrum is more slender than in Hyas. For both the generic name Stenarynchus, Lamarck, 1818, was long accepted, but Macropodia was instituted by Leach for the same species three years earlier. M. tenuirostris of Leach was for some time supposed to be a synonym of Inachus longirostris (Fabricius). The latter form, however, has now been shown by Miss Rathbun to be a synonym of M. rostrata, so that M. tenuirostris takes rank as an independent species. Less interesting to the intellect but more welcome to the palate is Cancer pagurus, Linn., the well-known representative of the Cyclometopa, or arch-fronted crabs. It belongs to the family Cancridae, and for mere purposes of recognition would not need to be described. It may, however, be noticed that technically the front of a crab is the part of the carapace between the orbits, but when we speak of cyclometopous or circular-fronted crabs, we refer to the segment of a circle including with the true front and the orbits also the two marginal spaces, which are commonly divided each into five teeth. These spaces in the great eatable crab form, in place of five dents, nine bluntish lobes. The supply of this species at Lowestoft in the spring of 1907 did not appear to be especially plentiful. Mr. Claude Morley notes that the Ipswich Museum possesses an abnormal claw of a specimen from Aldeburgh. In the same institution he observed Portunus marmoreus. Leach, brought in by Southwold fishing-boats, and Carcinus maenas (Linn.), which he speaks of as doubtless abundant. A dead specimen was noticed in 1907 at Lake Lothing, and incidentally the species is mentioned as occurring in the river at Yarmouth in 1869. While waiting for the tide to turn, ' Robertson and Brady sat down by the side of a little stream, where a great many shrimps were playing or hunting for prey under a little cascade. There was a little shore-crab, Carcinus maenas, stationed at the corner, making many a grab at the shrimps, but they eluded each and every attempt he made by bounding backwards with wonderful dexterity.' ' The genera Carcinus and Portunus both belong to the family Portunidae or swimming crabs, and agree in regard to the pleon, which in the female is fully segmented, but in the male has only five segments, the middle three in that sex being coalesced into a single piece. In Portunus the last joint of the last legs (fifth pair of perae- opods) is far more expanded than in Carcinus. Really the audacious C. maenas is so much given to walking about in the open air that a specially paddle-shaped toe for natatory purposes would be an inconvenient piece of equipment. The Oxystomata, or sharp-mouthed crabs, owe their name not to any rostral prolongation, but to the narrowing forwards of the buccal or mouth area. From this tribe Metzger reports Ebalia cranchii. Leach, as taken in 23 fathoms, south-east of Yarmouth, and E. tumefacta (Montagu) in 23 fethoms, east-south-east of the same town.' They belong to the family Leucosiidae, in which the afferent channels to the branchiae open at the antero-lateral angles of the endostome or buccal cavity, and the efferent channels traverse it in the middle line. The branchiae are fewer than nine in number on each side. According to Leach, Montagu's species has only three tubercles on the carapace, while his own has five. He further specifies that in Montagu's species the pleon of the male has not only the third to the fifth segments coalesced, but also the sixth and seventh, the latter two apparently being separate in C. cranchii. To an eye unsophisticated by ' Nordseefahrt der Pommerania (Jahresbericht coram, zur wissenschaftlichen Untersuchung der deutschen Meeres in Kiel, 1875), 294. ' The Naturaftst of Cumbrae (1891), 256. • NordseefoArt der Pommerania, 293. 154
