CRUSTACEA. 271 



anterior margins ; in the first two pairs there is also a small spinule 

 at the distal end of the posterior margin. Ground-colour yellowish ; 

 the transverse imbrications of the carapace and legs are red ; the 

 carpus- and merus-joints of the ambulatory legs are also banded with 

 red. Length and breadth of the carapace of the largest specimen 

 (a female with ova) a little over 4 lines (9 millim.), of chelipede, 

 when extended, 9| lines (20 millim.). 



Two adult females and three males (one very small) are in the 

 first collection from Port Denison, 4 fms. (Nos. Ill, 122), and a 

 small male from Port Molle, 5-12 fms. (No. 118) ; in the second 

 collection is an adult female from Prince of Wales Channel, 7 fms. 

 (No. 109), and two small specimens from Thursday Island, 4-5 fms. 

 (No. 165). 



The description is taken from the largest female ; in the smallest 

 specimen the anterior margin of the front is minutely denticulated. 

 There are in the British-Museum collection three specimens ob- 

 tained off Cape Capricorn (15 fms.). White's typical specimen is 

 from the Philippine Islands, Corregidor (Cuming). 



In the last consignment received from H.M.S. ' Alert ' are speci- 

 mens from the Seychelles. 



This species cannot, I think, be confounded with any of the 

 numerous Oriental forms described by Milne-Edwards, Dana, Stimp- 

 son, and Heller. 



It is evidently nearly allied to P. scabricula, Dana *, from the 

 Sooloo Sea, and to P. vrilitaris, Heller t, from the Nicobars, in both 

 of which the spinulation of the carapace is different and the palms 

 of the chelipedes externally pubescent. In P. scabricula the series 

 of spines along the posterior margin of the wrist seem to extend 

 along its whole length ; and Heller makes no mention of the pro- 

 minent spine on the upper margin of the orbit in his description of 

 P. militaris, which in P. annulipes seems to occupy the position of 

 the obtuse-lateral frontal lobes mentioned in his description. 



Mr. Haswell (Catalogue, p. 146) refers certain specimens collected 

 at Port Denison to the Petrolisthes clentatus of M.-Edwards + ; but as 

 he only cites M. -Edwards's verj r short diagnosis and adds nothing 

 respecting the Australian specimens, I am unable to say whether 

 they are distinguishable from the species I have designated P. has- 

 welli or from P. annulipes. M.-Edwards's types were from Java, and 

 seem to be distinguished from the Australian species by having the 

 posterior margin of the carpus of the chelipedes " dentele en scie." 



15. Petrolisthes? corallicola (Haswell)? (Plate XXIX. fig. C.) 



? Porcellana corallicola, Haswell, Proc. Linn. Soc. N. S. Wales, vi. 

 p. 759 (1881) ; Cat. Austr. Crust, p. 150 (1882). 



Carapace much longer than broad, the gastric and hepatic regions 



* U.S. Expl. Exp. xiii. Crust, i. p. 424, pi. xxvi. fig. 13 (1852). 

 t Crust, in Eeise cler Novara, p. 75 (1865). 

 % Hist. Nat. Crust, ii. p. 251 (1837). 



