MUSEUM OF COMPARATIVE ZOOLOGY. 167 
antenne are about equal in length to the carapace without the rostrum; the 
second segment is armed with a long and sharp external spine; there is, more- 
over, on the antenna of the right side a movable thorn-like acicle equal in 
length to the last two segments of the peduncle together; the acicle is armed 
with a small tooth on the external margin midway between the base and the 
tip. There is no trace of an acicle on the left antenna. As the type specimen 
is the only one obtained, it is impossible to tell whether the acicle is normally 
present or absent. ‘The last segment of the peduncle is nearly twice as long as 
the penultimate segment. The chelipeds are furnished with scattered tuber- 
cles, a few of which assume a spiny form. The left cheliped is rather slen- 
derer than its fellow. The ambulatory legs are long and rather slender, their 
meri sparsely furnished above with tubercles, which tend to a spiny form on 
the anterior and posterior margins; at the distal end of the anterior margin 
of the meri there is a prominent spine-like tooth ; the carpi and propodi are 
armed with teeth, chiefly on the anterior margins; the dactyli are equipped 
with four short spines (two superior and two lateral) near the proximal end. 
The abdominal segments (of the female) are roughened by low tubercles, and 
dentate on their margins. The lateral teeth of the marginal plates of the right 
side are drawn out into long spines. The tergal plate of the second abdominal 
segment is completely fused with the epimera, showing no trace of an in- 
tervening suture. The marginal (episternal?) plates of this segment are 
bounded within by a distinct suture. 
Length of carapace, excluding rostrum, 79 mm. ; rostrum, 14 mm.; breadth 
of carapace, 79.5 mm.; length of posterior pair of ambulatory legs, 193 mm.; 
merus, 58.5 mm.; carpus, 31 mm.; propodus, 54 mm.; dactylus, 33 mm. 
Station 3384. 458 fathoms. 1 female. ; 
This species finds its nearest relative in Z. murrayi Henderson (Rep. Chal- 
lenger Anomura, p. 48, Plate IV.), from the distant Prince Edward Island in 
the Southern Ocean. The latter species differs from LZ. panamensis in having 
a much longer rostrum, which is forked at the end, a more oval and spiny cara- 
pace, shorter external antennal spine, more spinose legs, etc. 
Family PAGURIDZ. 
Cancellus tanneri, sp. nov. 
Differs from @. canaliculatus (Herbst) in having a much shorter and broader 
abdomen, in the lobate character of the marginal crests of the first and second 
pairs of legs, in the pubescence of the thorax and abdomen, and in the short- 
ness of the antenne. From C. typus M. Edw., it is distinguished by having 
the anterior border of the carapace less deeply incised on either side of the ros- 
trum, and the telson squarely truncated posteriorly, not notched in the middle; 
the cox of the last pair of legs, too, present a very different shape, since they 
lack the prominent anterior lobe observable in C. typus. C. purfaiti A. M. Edw. 
