■•k 



344 



on the upper border, but also the two on the outer resp. the inner surface, that are directed 

 from the articulation of the fingers almost to the middle of the palm, are quite conspicuous 

 and the outer surface of the immobile finger is deeply concave. The inner margin of ischium 

 and merus of the larger cheliped is finely denticulate. 



Remarks. Of the other species of the Macrochirtis group A. socialis Heller from 

 New South Wales is perhaps the most closely related. In this species, however, the lateral 

 margins of the rostrum bear no hairs, the orbits present a small spine anteriorly and the basal 

 spine of the outer antennae extends almost to the end of 2°'^ antennular article (though in 

 Fig. I of Plate X of the "Novara-Reise" it appears much shorter, not longer than 1=^' article). 



General distribution: Mauritius (Richters) ; Dar-es-Salaam (Ortmann) ; Madagascar 

 (Coutiere); Maledives (Coutiere); Ternate (de Man); Tahiti (Ortmann); Rotuma (Borradaile) ; 

 Fernando- Veloso (Coutiere); Congo (Coutiere); Gulf of California (Coutiere). 



III. Crinihts group. 

 Ilia. Obeso-mamis subgroup. 



10. Alpheiis microstylus (Sp. Bate).. 



Betaeus microstylus C. Spence Bate, Report Challenger Macrura, 1888, p. 566, PI. CI, fig. 6. 

 Alpheiis microstylus H. Coutiere, Alpheidae Maid, and Laccad. Archip. 1905, p. 884, Pi. 



LXXVI, Fig. 23. 

 Alpheiis obesomanus J. G. de Man, in: Archiv f. Naturg. 53. Jahrg. 18S8, p. 520 and in: 



Abhandl. Senckenb. Naturf. Gesells. XXV, 1902, p. 867 — 869. 

 Confer: H. COUTIERE, Les "Alpheidae", 1899, p. 223, Fig. 270 — 272. 



Stat. 125. July 1S/19. Anchorage oft' Sawan, Siau-island. Reef, i male and i egg-bearing 



female. 

 Stat. 144. August 7/9. Anchorage north of Salomakiee-(Damar)-island. Reef, i young male. 



The male from Pulo Edam (Bay of Batavia), described by me (1. c.) in 188S and in 

 1902 under the name of A. obesomamts Dana, is lying before me and proves to belong to 

 A. microstylus (Sp. Bate). 



The male and the female from Stat. 125 are respectively 18,5 mm. and 20 mm. long, 

 this species attains, however, a length of 25 mm. In all the specimens the rostrum is developed. 

 In the male from Stat. 125 the acute rostrum distinctly reaches beyond the orbital margins 

 and measures abjDut one-fourth the visible part of the i^' antennular article. The 2"'^ article, 

 0,9 mm. long and 0,33 mm. thick, appears slightly more than one and a half as long as the 

 visible part (0,56mm.) of the i^' and almost 3-times as long as thick; 3'^'^ article two-thirds 

 of the 2°^^ and a little longer than the i*'. Stylocerite acute, pointed, reaching to the distal 

 3'''i part of i^' article. The scaphocerite which is cleft to the middle and the lamina of which 

 is fringed with long, feathered hairs, appears just as long as the carpocerite but extends a little 

 beyond the far end of the antennular peduncle; the scaphocerite is just 3-times as long as 

 broad in the middle. 



The larger chela closely resembles the accurate figures 270 and 271 in Coutiere's work 



