84 
PACIFIC SCIENCE, Vol. VII, January, 1953 
well, except that the large chela is somewhat 
more slender and its merus does not bear the 
two movable spines found in the type. 
However, the second male, from the island 
of Hawaii, shows a few notable differences. 
The rostrum, the stylocerite, and the lateral 
spine of the basicerite are all shorter, with the 
rostrum and the stylocerite reaching only to 
near the end of the first third of the second 
antennular article, and the lateral spine of the 
basicerite reaching only to the middle of the 
visible portion of the first article. The orbital 
teeth are half the length of the rostrum, and 
the orbital hoods are slightly less inflated. 
The large chela is 2.7 times as long as broad 
instead of 2.2, and the fingers occupy slightly 
over 0.5 of the length of the chela instead of 
slightly more than 0.25. The ratio of the car- 
pal articles of the second legs is slightly differ- 
ent — 10 : 10 : 8 : 6 : 16, with the second arti- 
cle slightly broader than long. The merus of 
the third legs is 3.5 times as long as broad in- 
stead of 3.0 times, and the propodus of the 
same legs bears four instead of five spines. 
Other parts of the two specimens showed 
close similarity. 
This male appears to be either within the 
normal range of variation or to be a closely 
related variety. It is likely that all the differ- 
ences may be due to simple growth differences 
combined with the inherent variation as shown 
in so many other species; in any case, the dif- 
ferences are not great enough, especially with 
only one specimen showing them, to warrant 
the erection of a new species or variety. 
RELATIONSHIP: This species is closely re- 
lated to two other Hawaiian species, C. gra- 
cilis var. simplex Banner and C. edmondsoni Ban- 
ner. The more conspicuous differences are 
given in Table 3. 
Of these characteristics, the most readily 
observed and decisive for rapid separation of 
this species are the carpus of the second legs 
and the dactylus of the third to fifth legs. The 
anterior region of the carapace also affords 
good characteristics, but it is more variable 
and therefore less reliable. 
According to de Man’s key (1911) in the 
Macrochirus Group, this species keys out to 
the two species C faceta (de Man) and C. 
spkndida (Coutiere) . It can be separated easily 
from these two species on the basis of the 
breadth of the articles of the second and third 
legs; by the greater breadth of the large chela; 
and especially by the lack of the longitudinal 
groove on the palm of the chela (characteris- 
tics taken mostly from de Man’s key; Cou- 
tiere’s original description, without figures, of 
C. spkndida was too brief to be of any value) . 
This species is apparently identical to Al- 
pheus sp. of Coutiere {loc. cit.) which was left 
unnamed because his three specimens each 
lacked the large chela. The form and propor- 
tions of the anterior body region and the pro- 
portions of the second legs, both shown in 
the plates, are identical to this species; the 
unique dactylus of the third legs was neither 
mentioned nor drawn. If the dactyli are the 
same, the specimens undoubtedly belong to 
this species. Incidentally, Coutiere believed 
that the species would belong to the Mega- 
cheles Group; the large chela shows its affini- 
ties to be with the Macrochirus Group. 
DISTRIBUTION: This rare species is evidently 
widespread among the larger Hawaiian Is- 
lands at least, for the four specimens are from 
three islands. The type came from water 20 
feet deep off Waikiki Reef, Oahu; an 8.8 mm. 
female came from 15-20 feet of water off 
Nanakuli, Oahu; an 8.0 mm. female came 
from 4 feet of water at Lahaina, Maui; and the 
aberrant 6.5 mm. male was collected by R. W. 
Hiatt from a head of Pocillopora meandrina 
Verrill in 5 feet of water at Halape, Kau Coast, 
Hawaii. Coutiere’s specimen came from Hu- 
lule Male Atoll, Indian Ocean. 
Crangon ventrosa (Milne-Edwards) 
Fig. 28 a-i 
Alpheus ventrosus Milne-Edwards, Histoire Na- 
turelle des Crustaces, 2: 352, 1837. 
Alpheus laevis Randall, Acad. Nat. Sci. Phila., 
Jour. 8(1): 141, 1839- 
