Pacific Alpheids II — Banner 
203 
Alpheus clypeatus Coutiere 
Alpheus clypeatus Coutiere, Fauna and Geog. 
Maidive and Laccadive Archipelagoes 2 
(4): 897, pis. 81-82, fig. 36, 1905. 
localities: Three specimens at E-l-306 
(fragmentary and uncertain); 4 at E-l-617; 
5 at E-l-648; 4 at E-2-343. 
Alpheus pachychirus Stimpson, I860 
For synonymy, see Banner, 1956. 
locality: Two specimens at E-l-290. 
Alpheus frontalis H. Milne-Edwards, 1837 
For synonymy, see Banner, 1956. 
locality: Two specimens at E-l-611. 
Diadema Subgroup 
Alpheus bidens (Olivier) 
Palaemon bidens Olivier, Encyclopedic Me- 
thodique, Histoire Naturelle 8: 663, 1811. 
Alpheus bidens H. Milne-Edwards, Histoire 
Naturelle des Crustaces 2: 353, pi. 24, figs. 
11, 12, 1837. 
Alpheus tridentatus Zehntner, Rev. Suisse de 
Zool. 2: 204, pi. 8, fig. 24, 1894. 
localities: Two specimens at E-2-360; 1 
at E-2-382. 
discussion: These specimens show con- 
siderable variation from each other despite 
the fact that there are only three specimens 
involved. On one specimen the dorsal den- 
ticles of the anterior carapace reach almost to 
the base of the eyes, while the other two are 
considerably shorter (but not placed as far 
posteriorly as indicated by de Man, 1911: ph 
17, fig. 80). The rostrum on one does not 
reach quite to the end of the first antennular 
article, on the second reaches slightly beyond 
it, and on the third reaches almost to the 
middle of the second article. The first anten- 
nular article bears one movable spine and two 
long setae in two of the specimens, but in the 
third carries one spine on one side and two 
spines (as shown by de Man) on the opposite 
article. On the merus of the large chela the 
armature varies, with one specimen bearing 
feeble spines on the inferior internal margin, 
only several exceedingly weak spines on su- 
perior margin, while the inferior external mar- 
gin carried only about 10 poorly developed 
serrations; on the second specimens the spines 
of the inferior internal are quite strong, the 
superior margin carries 7 short but strong 
spines, and the serrations on inferior external 
margin are marked; the third specimen is 
intermediate between these two. 
However in other characteristics, these 
specimens compare sufficiently well to the 
descriptions of the species that these varia- 
tions cannot permit one to consider them as 
other than this species. 
Alpheus diadema Dana, 1852 
For synonymy, see Banner, 1956. 
localities: Two specimens at E-l-149; 1 
at E-l-290; 2 at E-2-343; 2 at E-2-360. 
Alpheus percyi Coutiere 
Alpheus percy i Coutiere, Soc. Philomath. Paris, 
Bui. 9(5): 21, 1908. 
Alpheus percyi Coutiere, Linn. Soc. London, 
Trans., Zool. II, 17(4): 426, pi. 64, fig. 22, 
1921. [Same description, figures added.] 
locality: Two specimens at E-2-382. 
discussion: This specimen agrees very well 
with the specimens from the Hawaiian archi- 
pelago except for the rostrum. In the Hawai- 
ian species the rostrum bears a low, obtuse 
but definite crest, but in these two specimens 
the rostrum is dorsally flat and smooth. While 
Coutiere does not discuss this characteristic 
in his original description, his figures in his 
1921 publication (figs. 22, 22 1 ) seem to in- 
dicate a condition similar to these Marshall 
specimens. It may be that the Hawaiian spec- 
imens will be found to represent a geograph- 
