154 
PACIFIC SCIENCE, Vol. XIV, April I960 
variable, with the range of variation not only 
bridging the supposed differences between the 
nominal species and subspecies, but also extend- 
ing beyond any previously reported condition. It 
is interesting to note that the specimens that 
agreed best with A. dorsalis were those from 
Raroia, not too far from the type locality of 
A. maruteensis, while the specimens from the 
Marshalls were more like the description of 
A. maruteensis. 
The exact status of A. mascarinicus Richters 
is not known, as the description, without figures, 
is inadequate. It may be a synonym of this spe- 
cies; it may be the same as, and take priority 
over A. indicus or A. amhoinensis; it may be 
regarded as a nomen dubium; or it may be a 
separate and valid species. Unless the type speci- 
men can be redescribed, we feel it is safest to 
consider it as a synonym of A. dorsalis. 
On many of these specimens, including the 
large group from the Marshalls, it was specified 
that they were collected from large sea urchins 
of the genus H etero centrotus; however, for some 
their habitat was specified as "coral” (as was 
that of Stimpson’s original specimen ) . Whether 
this indicates that the species normally lives 
only on sea urchins but may desert them if the 
urchin is disturbed, as by a collector, or whether 
it indicates that the species may live either on 
coral or sea urchins is not known. At least, no 
significant differences were found between those 
collected from urchins and those collected from 
unspecified "coral.” 
Athanas amhoinensis (de Man, 1910£: 25- 
27, figs. 1-6) is, at least, closely related to 
A. dorsalis , more closely than A. indicus (Cou- 
tiere ) ; it may be found to be a synonym. How- 
ever, as none of the specimens in the collection 
approach the proportions of the slender chela 
and narrow telson given by de Man as specific 
characteristics, there is no evidence that the two 
should be combined. 
distribution : Stimpson’s original specimens 
came from Hongkong and it has been reported 
from Djibouti, Indian Ocean, Indonesia, New 
Caledonia, Kermadec Islands and Samoa. In the 
present collection we have about 70 specimens, 
the majority from the Marshall Islands, 2 speci- 
mens from Canton Island, 1 from Fiji and 6 
from the Tuamotus. At least 50 of the speci- 
mens were commensal with the sea urchin 
H etero centrotus. 
REFERENCES 
Balss, Heinrich. 1915. Die Decapoden des 
Roten Meeres: Macruren Expeditionen S. M. 
Schiff "Pola” in das Rote Meer. Ergebn. Zool. 
30: 1-38, 30 figs. 
Banner, Albert H. 1956. Contributions to 
the knowledge of the Alpheid shrimp of the 
Pacific. I. Collections from the Mariana Arch- 
ipelago. Pacif. Sci. 10(3): 318-373, figs. 
1-23. 
Barnard, K. H. 1950. Descriptive Catalogue of 
South African Decapod Crustacea. Ann. S. 
Afr. Mus. 38. 837 pp., 154 figs. 
Borradaile, L. A. 1898. On some crustaceans 
from the South Pacific. Part III. Macrura. 
Proc. Zool. Soc. Lond. 1898: 1000-1015, pis. 
63-65. 
Chace, Fenner A., Jr. 1955. Notes on shrimps 
from the Marshall Islands. Proc. U. S. Natl. 
Mus. 105(3349): 1-22. 
Coutiere, H. 1897. Note sur quelques alpheides 
nouveaus ou peu connus rapportes de Dji- 
bouti. Bull. Mus. Hist. Nat., Paris 3(6): 233— 
236. 
1899. Les "Alpheidae,” Morphologie, 
externe et interne, formes larvaires, bionomie. 
Theses presentees a la Faculte des Sciences de 
Paris. . . Ser. A, No. 321 [no. d’Ordre 980}. 
599 pp., 409 text figs., 6 pis. Masson et Cie, 
Paris. [Also: Ann. Sci. Nat. VIII, Zool. 9: 
1-560.} 
1903. Note sur quelques Alpheidae des 
Maldives et Laquedives. Bull. Soc. Philom. 
Paris IX, 5(2): 72-90. 
1904. Note sur le commensalisme de 
X Arete dorsalis var. pacificus Coutiere, d’apres 
les notes de M. L. Seurat, naturaliste, a Riki- 
tea (lies Gambier). Bull. Mus. Hist. Nat., 
Paris 10(2): 58-60. 
1905^. Note sur quelques Alpheidae 
recueilles par M. G. Seurat a Marutea (lies 
Gambier). Bull. Mus. Hist. Nat., Paris 11 
(1): 18-23. 
190 5 A Marine Crustacea, XV. Les Al- 
pheidae. IN: Fauna and Geography of the 
Maidive and Laccadive Archipelagoes [J. 
