84 IOWA STUDIES IN NATURAL HISTORY 
specimens the latter count rises to 20. The mandible has a 
three jointed palp. The hepatic spine is well developed, and 
as characteristic of the genus, is situated a little below and not 
far behind the antennal spine. The fingers and palm of the 
first legs are subequal, the carpus is about twice as long as the 
chela and about equal to the merus in length; the dactyls of 
the last three pairs of legs are simple, long and slender, about 
one-fourth the length of the propodus. The telson is about as 
long as half the fifth and the sixth segments of the abdomen 
taken together. 
Periclimenes antiguensis, new species 
English Harbor, Antigua, electric light, July, 1918; 1¢4 
holotype. 
Rostrum straight, distally a little upturned, as long as rest of carapace, 
and about two and a half times as long as the antennular peduncle; 
armed above with nine teeth, of which the first is about over the distal 
margin of the second segment of the antennular peduncle; dorsal teeth 
regularly spaced, distance from last tooth to the acute tip twice that 
between last tooth and the penultimate one; below there are six teeth, 
the first of which is about under the third dorsal and the last a little in 
advance of the last dorsal, the second is under fifth dorsal and the third, 
fourth and fifth about under the intervals between the sixth, seventh, 
eighth and ninth teeth above; behind the first dorsal tooth the upper 
margin of the rostrum broadens out to form an elongate, narrow-trian- 
gular, flattened area on a level and confluent with the dorsum of the 
carapace; supra-orbital or rather orbital ‘‘spine’’ a blunt prominence, 
the anterior margin of which in dorsal view forms approximately a 
right angle with its lateral margin which is parallel to the longitudinal 
axis of the carapace; apex of the angle slightly produced, and blunt, a 
little behind the anterior margin of the carapace, and about in line, in 
lateral view, with the lower margin of the eye-stalk; antennal spine well 
developed, hepatic spine wanting. 
Basally the upper, outer, thicker antennular flagellum appears con- 
siderably swollen, due to the short, thick, closely apposed accessory or 
secondary ‘‘flagellum’’ which it carries; this apparently is made up of 
four free segments, in addition to, possibly, two or three others which are 
fused with the primary flagellum; the enlarged external view of the right 
antennule with respect to the greater part of the base of the bifurcate 
flagellum is largely tentative, as the mass of thick hairs covering the 
lateral face of the accessory flagellum made it virtually impossible to 
satisfactorily determine the exact segmentation; just before the beginning 
of its distal third the lower, medial margin of the basal segment of the 
antennular peduncle carries a stout spine; the eyestalk reaches about to 
the middle of the second segment; the second segment of the peduncle 
