BEACHTUEA EEOM TORRES STRAITS. 9 



punctations mark off more or less prominent accessory tubercles which surround the base 

 of each large tubercle. The frontal lobes in A. ealculosa are smooth or indistinctly 

 granulated on the edge, while in A.yranulata they are edged with pointed granules. In 

 A. ealculosa the outer surface of the hands bears smooth, bluntly conical tubercles 

 arranged in longitudinal rows ; in ^. cjranulata the tubercles are lower, surrounded bv 

 prominent and pointed accessory tubercles, and the arrangement in roAAs is less reo-ular. 

 The walking-legs are covered with tubercles rounded at the tip, smooth, and larger in 

 size than in A.grannlata, where they are low, pointed, and more numerous. The merus 

 joint of the last pair of legs is strongly serrate above, the serrations increasing in height 

 towards the distal end, and its posterior face is nearly smooth. In A. granulata the 

 seiTations of the upper edge are small and irregular, and the posterior surface is covered 

 with granulations. The sternum and abdomen, especially in the male, are smooth, with 

 scattered pimctatious, while in ^. (jraunlata the same regions are usually much granulated, 

 at least posteriorly. 



In his report on the Crustacea collected by H.M.S. ' Alert,' Mr. Miers has described 

 and hgured, imder the name of Enxanthns tuherculosm, a species which I believe, after 

 examination of his type specimens, to be identical with the present. Mr. Miers writes, 

 " As the basal antennal joint enters well within the inner orbital hiatus, this species must, 

 I think, be referred to the genus Enxanthns^ In his specific description the account of 

 the basal antennal joint is qiialified by the words " in the adult,'" and certainly the 

 difference in this respect between the largest and the smallest of the specimens he was 

 describing is conspicuous enough to have suggested a doubt as to the validity of a generic 

 distinction resting on this point alone. As a matter of fact it is easy to find specimens 

 both of the present species and of A. granulata in which the l)asal antennal joint enters 

 quite as far into the orbital hiatus as in any but the largest of Miers's specimens *. The 

 individual which he figures, and from which his description is mainly drawn, is a large 

 male, 23 mm. in length. The carapace is rather wider than in smaller specimens, the 

 breadth-ratio being about l"i3, and the tuberculation of the carapace is very strongly 

 developed. The smaller specimens associated with this by Mr. Miers, and obtained bv 

 the ' Alert ' in the vicinity of Torres Straits, are all but identical with the specimens in 

 the present collection from the same locality. Mr. Miers further states that the smaller 

 specimens "have much the aspect of certain Actceo!, e. g., A. f/raitnlata (Aud.) and 

 A. carcharhts, White ; from both of which species they may be distinguished upon the 

 most superficial examination by the smoothness of the sternum and post-abdomen." In 

 spite of the emphasis of the last sentence, I find in the British Museum collections 

 specimens determined by Mr. Miers as^. granulata (among others the one referred to in 

 his ' Challenger ' Report, p. 120) which resemble in every respect the smaller types of his 

 " Euxanthus tuberculosm." The few specimens referred to A. ealculosa in the British 

 Museum collection are rather different in appearance from our Torres Straits specimens, 



* Paulson (whose work ilr. Miers had not .seen) had already established a new genus Eu.vanth,»/cs for the 

 reception of Actn'Ci granulata ou account of the structure of its antennal region, which he figures (■ (!ruritacea of the 

 Red Sea " (Russian), Kiev, 187;', p. 33, pi. vi. figs. 3 & 3 a). 



SECOND SERIES. — ZOOLOGY, VOL. VIII. 2 



