CBTTSTACI.V. 2^7 



which is distinguished by having a small but well-developed spinule 

 on the outer side of the antennal scale at base, and the fingers of 

 the smaller chelipede slender, arcuated, considerably longer than 

 the palm, thickly clothed with long hair on Hair inner margins, and 

 having between them an interspace when closed. In the adult the 

 fingers are sometimes elongated to a remarkable degree, three times 

 as long as the palm in one specimen. This form I propose to 

 designate Alpheus gracilidigitus. 



Crangon monopodiinn, Bosc *, is very possibly this or an allied 

 species. As, however, it is impossible to identify that author's brief 

 description and rude figure as given in his second edition (1830) with 

 any species with certainty, and as his designation has never been 

 adopted by any subsequent writer. I prefer to retain Audouin's name 

 A. edwardsii, about which there is no uncertainty and which has 

 been used by several authors of repute. I have never seen the first 

 edition of Bosc's work. 



Both the Alpheus edwardsii, as described by Dana from Cape- 

 Yerd specimens, and the A. pacijicus, Dana, from the Sandwich 

 Islands, differ in having the second joint of the carpus of the second 

 pair of legs much shorter than the first joint, but are probably mere 

 varieties of the typical A. edwardsii. 



The species I described from the Samoa Islands as A. lineifer t is 

 allied to A edwardsii, but may be distinguished by the smoother 

 chelipede and the existence of a well-developed spine on the outer 

 side of the peduncles of the antenna?. It may perhaps be the young 

 of Alpheus parvirostris, Dana, from the Balabac Straits ; but the first 

 joint of the carpus of the second pair of legs is relatively shorter, 

 and the large chela of the first pair relatively narrower and more 

 elongated than in Dana's figure. 



6. Alpheus obesomanus, Dana. 



A small example from Port Molle, 5-12 fms. (Xo. 118), is re- 

 ferred to this species. 



Several small specimens are in the British-Museum collection from 

 Ovalau, Fijis (H.JI.S. '■Herald'). Dana's types were also from the 

 Fiji Islands. Dr. F. Bichters has recently recorded this species 

 from the Mauritius (Isle des Fouquets). 



This species is remarkable on account of the turgid form of the 

 larger chelipede and the great elongation of the second carpal joint 

 of the second pair of legs. 



7. Alpheus gracilipes, Stimpson. 



I thus designate a specimen from Port Molle, obtained on the 

 beach (Xo. 05), and another small example from Flinders Island, 



* Hist. Nat. Crust, ii. p. 96, pi. xiii. fig. 2 (1802). 

 t Ann. & Mag. Nat. Hist. ser. 4, xyi. p. 343 (187o). 



