, 
422 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. — 
Station 875; 100 fathoms. 
Another and very much smaller specimen, from station 876, 120 fath- 
oms, though differing very much from the larger specimen, is probably 
the young of the same species. The carapax of this specimen is propor- 
tionately longer; the orbital sinuses are much larger; the lateral spines 
of the front are more slender and much longer, longer even than the 
rostral tooth, and curved slightly outward and upward toward the tips; 
and the lateral spines are much longer and directed more outward. 
There is a small tubercle upon the third somite of the abdomen, and in 
place of the tubercle on the fourth somite there is an acute spine, much 
longer than the somite itself. There is also a small spiniform tubercle 
on the lower side of the ischium of the third pair of ambulatory legs. 
mm. 
henchhrofcarapax, ineludime TOSiUIMl. --\ see wise eal eaminle aed alae sia iaieiee eee ee 10.3 
Breadth of carapax just back of lateral spimesy,.<(s22--<s(-- <a eee) a- ois i = er 5.7 
Breadth of carapax between tips of lateral spines. .-----:--5---2--+- =-s..«-4-5 6.8 
Breadth of front berween tips of lateralispimes --< 2-0 ---. Secn once en eee 3. 6 
Wen oth OL LOStLWMs- osiccins min oie o/elaisiieisisie sec's/csiele osiiais aialalcicinrs Saineiem sie esis auscioniee 1.5 
Hemipagurus, gen. nov. 
The genus for which this name is proposed is allied to Spiropagurus 
Stimpson (Proce. Acad. Nat. Sci. Philadelphia, x, 1858, p. 236 (74), 1859), 
but differs conspicuously in the form and position of the sexuai append- 
age of the last thoracic somite of the male. In Spiropagurus this 
appendage (formed by the permanent extrusion of a portion of the vas 
deferens) arises from the coxa of the left side of the last thoracic somite; 
while in the genus here proposed it arises from the corresponding coxa 
of the right side, is shorter than in Spiropagurus, and curved in one 
plane round the right side of the abdomen. 
The carapax is short and broad, and the anterior margin is obtuse, 
and does not wholly cover the ophthalmie somite between the eyes. 
The portion in front of the cervical suture is indurated, but all the rest 
of the carapax is very soft and membranaceous, without any distinet 
induration along the cardiaco-branchial suture. The ophthalmic scales 
are well developed. The eye-stalks are short and the cornea expanded. 
The antennule, antennee, and oral appendages are similar to those in 
Eupagurus; the exopods of all the maxillipeds are, however, propor- 
tionally much longer than in that genus. There are eleven pairs of 
phyllobranchiz, arranged as in Hupagurus bernhardus, but the two ante- 
rior pairs connected with the external maxillipeds are very small and 
rudimentary, and composed of a few slightly flattened papilli, so that 
they are, strictly speaking, trichobranchiz. The chelipeds are slender 
and unequal. The first and second pairs of ambulatory legs are long, 
and have slender, compressed, and ciliated or setigerous dactyli; the 
third pair are only imperfectly subcheliform. 
In the male, the second, third, and fourth somites of the abdomen 
bear small appendages upon the left side, as in most of the allied genera, 
