16 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 105 



in addition to the sexual differences involving* tlie outer antennular 

 flagelliun and the first chela noted by Coutiere (1905, p. 855) in A. 

 gardineri and A. doliehognatha. 



In the immature specimen from Enirik Island, the antennular 

 segments are much more robust and there are but six or eight swollen 

 segments in the outer antemiular flagellum. 



The male holotype is approximately 12 mm. long and has a carapace 

 length of 3.6 mm. The male paratype from Bogombogo Island has 

 a carapace length of 4.7 mm., the ovigerous female from Bokonfuaaku 

 Island has the carapace 3.9 mm. long, and the immature individual 

 from Enirik Island has a carapace length of 1.8 m.m. 



This species is closely related to, if not identical with, A. gardineri 

 Coutiere. It differs from Coutiere's description and figures (1905, p. 

 854, figs. 127, 128), as well as from a Siamese specimen tentatively 

 identified as A. gardineri by W. L. Schmitt (Suvatti, 1938, p. 47), in 

 the following particulars: the rostrum is triangular rather than rounded 

 and is not delimited laterally by grooves on the carapace; the anten- 

 nular peduncle is stouter, the penultimate segment being about 2)2 

 rather than 4 or more times longer than wide; the stylocerite is 

 slightly longer, usually overreaching rather than falling short of the 

 end of the proximal segment; and the antennal scale reaches nearly or 

 quite to the distal fifth of the penultimate antennular segment rather 

 than extending but little beyond the middle of that segment. All 

 these distinctions may prove to be unimportant when additional 

 material becomes available, but it seems advisable for the present to 

 consider the Marshall Islands form distinct, in order to stress the 

 differences. The species is close to Automate sp. de Man (1911b, p. 

 140, pi. 1, figs. 2-2d), but whether any or all of these forms are dis- 

 tinct must remain for later workers to decide. 



Athanas djiboutensis Coutiere 



Athanas djiboutensis Coutiere, 1897, p. 234; 1905, p. 853, fig. 129.— Tattersall, 

 1921, p. 368. 



Bikini Atoll: Namu Island; reef inside lagoon; Apr. 3, 1946; M. W. 

 Johnson; 1 male. — Same; April 4, 1946; 2 ovigerous females. — Bokon- 

 fuaaku Island; intertidal potholes; May 16, 1946; M. W. Johnson; 1 

 male, 1 ovigerous female. — Enirik Island; intertidal; 1946; M. W. 

 Johnson; 2 males. 



Eniwetok Atoll: Bogen Island; intertidal potholes; May 21, 1946; 

 M. W. Johnson; 1 male. — Bogombogo Island; intertidal; May 31, 

 1946; M. W. Johnson; 1 ovigerous female. 



Rongelap Atoll: Eniaetok Island ; intertidal potholes; June 16, 1946; 

 M. W. Johnson; 1 male. — Burok Island ; intertidal coral; July 18, 1946; 

 M. W. Johnson; 1 ovigerous female. 



