422 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 



Station 873; 100 fathoms. 



Another and very much smaller specimen, from station 876, 120 fiith- 

 oms, though (littering 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 nuich larger; the lateral spines 

 of the front are more slender and much longer, longer even than tlie 

 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. 



Length of carapax, including rostrum 10.3 



Breadth of carapax j ust hack of Uiteral apines 5. 7 



Breadth of carapax between tips of lateral spines 6. 8 



Breadth of front between tips of lateral spines 3. 6 



Length of rostrum 1.5 



Hsmipagurus, gen. nov. 



The genus for which this name is proposed is allied to Spiropagurus 

 Stimpson (Proc. Acad. Nat. Sci. Philadelphia, x, 1858, p. 230 (74), 1859), 

 but differs conspicuously in the form and position of the sexual ajjpend- 

 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 ophthalmic 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 distinct 

 induration along the cardiaco-branchial suture. The oi>hthalmic scales 

 are well developed. The eye-stalks are short and the cornea expanded. 

 The antennulae, antennae, and oral appendages are simihir to those in 

 JSujjagurtis; the exopods of all the maxillipeds are, however, propor- 

 tionally much longer than in that genus. There are eleven pairs of 

 phyllobranchiiB, arranged as in Eupagurus hernhardus, but the two ante- 

 rior pairs connected with the external maxillipeds are very small and 

 rudimentary, and composed of a few slightly flattened papillte, so that 

 they are, strictly speaking, trichobrauchiae. 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, 



