| OCR Text |
Show 698 MR. W. A. CUNNINGTON ON A NEW [May 16, possible the method adopted for the distinction of genera and species in its nearest allies, it may be thus diagnosed:- LIMNOTHELPHUSA, gen. nov. Carapace moderately convex, antero-lateral margins arcuated and armed with spines. Front somewhat deliexed, nearly straight, aud more than one-third the width of the carapace. Orbits large, with prominent inner subocular tooth. Eyes large, with peduncles short and stout. Second joint of antenna simple, not distorted by deflexed front. Merus of external maxillipeds roughly quadrilateral, the carpus being attached towards its inner front angle. Ambulatory legs considerably compressed. LIMNOTHELPHUSA MACULATA, sp. nov. (Plate XXXVIII.) Regions and sutures on carapace moderately marked. Posterolateral regions exhibiting an irregular series of small, slightly oblique and granular ridges. Post-frontal crest distinct, with median notch and partial lateral interruptions, but not extending to margins. Antero-lateral margins shorter than postero-lateral, armed with 2-3 spines, in addition to that at the outer angle of the orbit. Second joint of antenna extending to under border of front, and bearing a short flagellum. Chelipeds in the male unequal, subequal in the female ; merus rather short, trigonous, with spine on inner margin ; carpus with two spines on inner margin. Ambulatory legs rather long and slender. Colour (in spirit) light yellowish brown, with dark brown or reddish spots. Dimensions as follows :- Adult male (largest specimen): mm. Length of carapace 12 Breadth of carapace 15*4 Length of larger cheliped about 21*7 Length of second ambulatory leg, about 21 Adult female: Length of carapace 11*5 Breadth of carapace 13-6 Length of cheliped about 12*8 Length of second ambulatory leg, about 14*1 While the carapace is here, as throughout the Thelphusine group, broader than long, that condition is somewhat less pronounced, giving an effect of greater squareness. The great relative breadth of the front and size of the orbits are features also specially noticeable, even at first sight. The prominent and distinct condition of the subocular tooth (fig. 2, t.so.) seems characteristic, while a crenulated subocular margin forms a further point of difference from other members of the group. The an-tennules, with their large basal joints, are situated in the normal transverse position, and the antenna? occupy the interior orbital hiatus. The external maxillipeds, while Thelphusine in character- |
