8 SMITHSONIAN MISCELLANEOUS COLLECTIONS 



one-ninth the width of the carapax ; the pterygostomian spine is the 

 smallest of the four. The parts about the head are nearly the same 

 as in D. gracilipes, except that the forks of the rostrum are rather 

 more slenderly pointed, and there is no tooth between the pterygos- 

 tomian tooth and that at the anterior corner of the buccal region. 

 The external maxillipeds nearly reach the bases of the internal an- 

 tennae, thus almost entirely concealing the epistome. The pterygos- 

 tomian region is depressed so as to form a deep channel leading for- 

 ward from the afferent branchial openings. This channel is bounded 

 externally by a high, sharp ridge fringed with long hairs. The feet 

 are stout; those of the second pair shorter than twice the length of 

 the carapax- Chelopoda more slender than the other feet and not as 

 long as the carapax ; the fingers slender, minutely denticulated within 

 and contiguous throughout their length. Color brownish above and 

 below ; smooth tips of dactyli red. 



A single specimen only (a male) of this species was taken; its 

 dimensions (including the spines) are: Length of carapax, 1.65; 

 width, 1.50; length of posterior spine, 0.17; of lateral spine, 0.17; 

 length of a foot of second pair, 2.54 inches. 



Taken in the dredge with a mass of Echini from a muddy bottom 

 at the depth of 20 fathoms, off Tamtoo Island, coast of China, near 

 Hongkong. 



Genus CHIONCECETES Kroyer 



4. CHIONCECETES BERINGIANUS ' Stimpson 



Chioncecetes behringianus Stimpson, Proc. Bost. Soc. Nat. Hist., vi, 84, 

 Feb., 1857; Jour. Bost. Soc. Nat. Hist., vi, p. 449, 1857. 



Peloplastus pallasii Gerst^ckER, Archiv fiir Naturgeschichte, xxii, 105, 

 pi. I, fig. I. 



Gerstsecker has given an excellent figure of this species in the 

 Archiv fiir Naturgeschichte for 1856, but his paper does not appear 

 to have been published before April, 1857; our name has, therefore, 

 priority. The entomologist of Berlin does not seem to have been 

 acquainted with Kroyer's genus Chioncecetes, to which the species 

 certainly belongs ; in fact, it is most closely allied to the type, C. 

 opilio. 



This species was found in Bering Strait and northward as far 

 as the expedition penetrated, many specimens having been dredged 

 by Captain Rodgers. It also occurred to the southward of the 

 strait as far as Matwi Island. It is found only in deep water and 



^Chioncecetes opilio (O. Fabricius). 



