146 
PACIFIC SCIENCE, VoL XIII, April, 1959 
moins profondement 'evolue’ que sa forme 
habituelle,” and that A. digitalis was a syno- 
nym of A. rapax. I believe a more logical ex- 
planation of this condition may be found in 
the process of either the normal replacement 
of a lost large chela, or the rather unusual 
replacement of both chelae. In the normal re- 
placement of the large chela during successive 
molts, the small chela grows larger and takes 
on the appearance of the small chela; the 
condition drawn may be an intermediate stage 
where the small chela is regenerated, and the 
growing large chela has its size but not its 
final characteristics. In the replacement of 
both chelae. Darby (1934: 349, et seq.) re- 
ported that if the timing of loss of the indi- 
vidual appendages was controlled, they were 
replaced not by normal large and small chelae 
but by chelae of "intermediate” development. 
Finally, many, but not all, of these speci- 
mens have the inferior external margin of the 
merus of the small cheliped bearing extremely 
fine and irregular movable spines or serra- 
tions; under ordinary magnification these are 
not noticeable, and even under 100 diameters 
of magnification it could not be discerned 
whether these projections were articulated. 
This, too, was not found in the regenerating 
chela mentioned above. 
Alpheus platyunguiculatus (Banner) 
Fig. 10^ 
Crangon platyungaiculata Banner, Pacific Sci. 
7(1): 130, fig. 47, 1953. 
LOCALITIES: 8 specimens, the largest a 34 
mm. ovigerous female, all collected from silt- 
buried coral heads in the intertidal mud flats 
behind the shoreward reefs of Kaneohe Bay, 
Oahu, Hawaii. Collected by A. H. Banner. 
DISCUSSION: Since the collection of the five 
specimens upon which the original description 
was based, continuing search has been made 
for more specimens of this species. As ex- 
plained in the original description, these 
shrimp appear to be confined to burrows in 
the muddy to sandy areas where the burrows 
can reach down through the loose substrate 
Fig. 10. Alpheus platyunguiculatus (Banner) and 
Alpheus rapax Fabricius, third maxillipeds, medial 
aspects, a, A. platyunguiculatus; b, A. rapax. Drawn to 
to the same scale. 
into buried coral heads. A section of inshore 
reef was found where the buried coral was 
loose and breakable; in this area these speci- 
mens were found, together with A. rapax 
(Fabricius). When only shallow holes were 
dug, several inches deep to the top of the im- 
bedded coral, only A. rapax w2iS found; when 
the imbedded coral itself was broken up from 
a depth of 8 inches or a foot, both A. platyun- 
guiculatus and A. rapax were found. It ap- 
peared that the A. rapax was probably carried 
down from the sides of the excavation. 
In the examination of these specimens an 
excellent specific characteristic was found to 
separate this species from A. rapax. In A. 
platyunguiculatus the middle article of the 3rd 
maxilliped bears a dense tuft of hairs, the 
longest reaching about one-third the length 
