522 
MR. H. N. RIDLEY ON THE 
Alpheus ROSTRATIPES, d. sp. 
Carapace smooth, anterior margin crescentically excavated, 
the sides of the excavation being formed by the ocular hoods, 
which are anteriorly produced but not 'furnished with spines, 
and not separated from the rostrum by a depression. Rostrum 
springing from the centre of the excavation, pointed, short, pro- 
jecting slightly in front of the ocular hoods, but not reaching 
the anterior margin of the first segment of the antennular 
peduncle. Antennular spine reaching to the middle of the 
second segment of peduncle. Segments of peduncle short, 
approximately equal in length ; second segment furnished ex- 
ternally with a small spine on its anterior margin. Antennal 
scale as long as the antennular peduncle, much shorter than the 
antennal peduncle. Basal segment of antenna furnished laterally 
with a conspicuous spine. 
One of the legs of the first pair absent. The dactylus of the 
remaining one (the smaller ?) closing vertically ; long, longer 
than the manus, curved, pointed blade-like, when closed ; crossing 
the thumb. Thumb almost as long as dactylus, and at the base 
twice as thick, gradually tapering to a sharp, upturned point, 
meeting manus at an obtuse angle. Manus elliptical, simple, 
without constrictions or depressions, furnished close to the 
dactylar joint on each side with two blunt teeth, those on the 
outer side being obscurely marked. Carpus furnished on its 
inner side with a small blunt tooth. Meros three-sided, flattened 
below, superior margin produced in front into a conspicuous 
projection. Carpals of the second pair of legs becoming pro- 
gressively shorter in the following order : — 1, 5, 2, 3, 4. 
Carpus and meros of third and fourth pairs not furnished 
below with a spine. Dactylus of fourth pair bifid, of third pair 
absent. 
Alpheus, sp. 
(Too mutilated for identification.) 
Carapace furnished in front with a small pointed rostrum, 
which projects slightly in front of the ocular hoods, but not 
nearly to the anterior margin of the basal segment of the 
peduncle of the antennula ; ocular hoods rounded and not spined. 
Basal spine of autennula reaching to the anterior margin of the 
basal peduncular segment. Second segment of peduncle longer 
than the third, approximately equal -to the first. Antennal scale 
