306 COLLECTIONS FKOM MELAUESLi. 



last segment, which are broadly rounded. The eyes are borne on 

 the broadly rounded postero -lateral lobes of the head. The first 

 segment of the peduncle of the antennules is about twice as long as 

 broad and considerably dilated ; the second joint, which is small but 

 moderately dilated, is received into a cavity at the distal end of the 

 first joint ; the flagella about 14-jointed. The peduncular joints of 

 the antennae are slender ; the flagella about 20-jointed. The ambu- 

 latory legs are very slender ; the merus, carpus, and propus or penul- 

 timate joints margined inferiorly with short stiff hairs, and, as in 

 other species of the genus, the dactyli bear a small subterminal 

 accessory claw. The rami of the uropoda are narrow, entire, nearly 

 straight, and rather densely hairy ; the outer rather shorter than the 

 inner ramus, and more acute at its distal extremity ; the inner long, 

 projecting by about half its length beyond the terminal segment. 

 Colour (in spirit) yeUowish white. Length a little over 4 lines 

 (9 millim.). 



.A single mutilated specimen was obtained on the beach at 

 Thursday Island, Torres Straits, and is evidently a male, the ventral 

 genital stylets being very distinctly developed. Two males are in 

 the Museum collection without special locality {J. B. Jukes), and 

 some specimens from Singapore received in the final consignment of 

 H.M.S. ' Alert.' 



I cannot identify it with any of the Australian species of this 

 genus recently described by Mr. Haswell. In the granulated seg- 

 ments of the body it resembles 0. hidentata and O. eoronata, Haswell, 

 both obtained at Griffith's Point, Victoria, but differs in the arma- 

 ture of the terminal postabdominal segment. There are specimens 

 in the British-Museum collection from Bass Straits (J. Maegillivray, 

 H.M.8. ' Eattlesnake ') which I refer to C. eoronata, having the 

 tubercles on the dorsal surface of the postabdomen disposed as in 

 Mr. HasweU's diagnosis, but differing in the acute inner ramus of 

 the uropSda. 



G. longistylis is also very nearly allied to the European C. truneata, 

 Leach, but is distinguished by the much longer and slenderer inner 

 ramus of the uropoda. However, I am not sure that the examination 

 of a sufficient series would not necessitate uniting the two species. 



9. Cerceis bidentata, M.-Edw., var. aspericaudata 

 (Plate XXXIII. fig. D.) 



Thus is designated with much hesitation a specimen (male) from 

 Prince of Wales Channel, 7 fms. (No. 169). As Milne-Edwards's 

 diagnosis is very brief, I subjoin the following description of the 

 principal distinctive characters presented by the specimen before 

 me : — 



The body is convex with the sides straight, and widens gradually 

 to the tail. Head subtriangulate, but with the anterior margin 

 rounded ; the rostral lobe is inflexed, and lies between the bases of 

 the antennules ; the postero-lateral lobes, which bear the small black 



