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PACIFIC SCIENCE, Vol. XIII, April, 1959 
the third to fifth legs. This piece is borne by 
the tendon that reaches to the "heel” of the 
dactylus and is ordinarily obscured by the 
spines at the end of the dactylus if the animal 
dies with the dactyl straight or flexed towards 
the propodus. In many of these specimens, 
however, the dactylus was bent back on the 
propodus in death, so that the extra plate is 
apparent. The extra piece fits into an emargi- 
nation of the inferior distal end of the pro- 
podus when the dactylus is straight or flexed. 
Other specimens of this species were re-ex- 
amined and it was found that this develop- 
ment was carried by specimens from all areas 
studied. Moreover, specimens of the closely 
related A. paragracilis were also found to have 
the same structure. 
Third, the outer uropods of these speci- 
mens bear several broad teeth on the distal 
articulation, and the inner uropod on its outer 
distal margin bears several small spines; 
neither of these characteristics was found in 
the specimens from Hawaii. This difference 
is not considered worthy of taxonomic 
emphasis. 
The single specimen from the Tuamotus 
differs from the Hawaiian specimens in two 
minor ways. First, the rostrum is slightly 
shorter instead of slightly longer than the 
orbital hoods; second, the third and fourth 
carpal articles of the second legs are 1.3 and 
2.0 times as long as broad instead of being 
broader than long. This latter characteristic 
may be important, but one specimen is not 
adequate for drawing such a conclusion. 
Alpheus paragracilis Coutiere 
Fig. Ga-d 
For synonymy, see Banner, Pacific Sci. 10(3): 
345, 1956. 
LOCALITIES: 1 Specimen, Station Y-252, 
Yap Island, Caroline Archipelago, under 
small rocks on outer reef; collected by R. W. 
Hiatt, 1946. Nine specimens, Midway Is- 
land, Hawaiian Archipelago; collected by Y. 
Speicer, 1941. 
Fig. 6. Alpheus paragracilis Coutiere, variation in the 
large chela, a, Male, 11.4 mm. long; h, male 10.8 mm. 
long; c, female, 11.4 mm. long; d, male, 9-6 mm. long. 
All drawn to the same scale. 
DISCUSSION: These specimens present an 
interesting series on the change of form of 
the large chela with growth. The smaller 
males, less than 9.0 mm. long, and the females ' 
of all sizes have similar chelae, about twice as 
long as broad, and about 3.5 times the length j 
of the fingers; the fingers of the dactylus are 
short, heavy, and rounded distally. However, 
on the largest male in the collection, 11.4 mm. 
long, the chela is 2.4 times as long as broad, 
and only 2.3 times the length of the fingers, 
and the dactylus is long, thin, curved and 
acute on the end. Between these two condi- 
