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Show 1902.J CRUSTACEA OF THE " SKEAT EXPEDITION." 377 pieces, of which the distal (tergal) broadens to the blunt distal end. Affinities.-This species is certainly closely allied to Dichelaspis warwickii Gray. The general external appearance is much the same, making allowance for its variability in this species, and the mouth-parts appear to agree essentially with the description of D. warwickii given by Darwin (Lep. pp. 121-122). But it differs in the fact that the valves are not thin and translucent, but thick and opaque ; in the distal broadening, and division into two parts, of the carina; in the shape of the tergum (despite its variability); and in the fact that the 1st cirrus is not " far removed from the 2nd," and that the rami of the 2nd are not unequal. Although the shape and fission of the carina is the most constant external feature, I have found it difficult to fix that fact satisfactorily in the specific name ; words such as bicctrinata, fissi-carinatci, or others suggesting rather a reduplication of the carina than a single carina formed of two pieces. I have, therefore, fixed on the horse-like shape of the tergum, which, though not constant, still evidently represents the typical form of that valve in the species, by which to designate the species ; hence the specific name equina. C. ISOPODA. X Y I. Genus C ym o tho a Fabr. 30. C ym o th o a strom a t e i Bleeker. Cymothoa stromatei Blkr. Act. Soc. Sci. Indo-Neerland. ii. p. 35, pi. ii. fig. 13 (1857). L o c .-------? Hah. " Mouth-parts of fish, chiefly of Ikan dalam." Six females and a small male. 31. C ym o th o a p u l c h r u m , sp. nov. (Plate X X X V . figs. 8-8 a.) Loc. Pulau Bidan. One female. Eyes invisible, lateral prolongations of the 1st thoracic segment reaching very nearly to the level of the front, which is rounded acuminate. Cephalic segment f as long as broad (4'5 : 6 mm.), superiorly depressed so as to form a shallow p it, 1st thoracic segment the longest, 2nd, 3rd, and 4th a little shorter and subequal, 5th, 6th, and 7th gradually becoming shorter, the 5th not abruptly shorter than the 4th; segments 1-6 rugose, the rugosities becoming gradually less marked on the hinder segments, the 7th smooth ; the lateral prolongations of the 1st segment smooth, curved forwards and inwards, bluntly pointed in front. Abdomen abruptly narrower than thorax, the segments gradually increasing in width to the 5th, which is as wide as the last thoracic, and the 6th, which is as wide as the penultimate thoracic, segments. 6th abdominal segment about twice as wide as long (15: 7 mm.), somewhat excavate in the anterior median line, and slightly |