MUSEUM OF COMPAKAT1VE ZOOLOGY. 41 



Also obtained in the U. S. Fish Commission dredgings off Block Island in 

 1880, Station 892, N. Lat. 39° 46', W. Long. 71° 5', 487 fathoms ; and Station 

 893, N. Lat. 39° 52' 20", W. Long. 70° 58', 372 fathoms. 



The long and spined rostrum and the long spines and teeth of the carapax 

 and abdomen give this gigantic species a very different aspect from the other 

 species of the genus ; but the oral appendages, the number and arrangement of 

 the branchise, and other structural details, agree perfectly with S. septemcarinata, 

 the type species of the genus. The present species is, however, much more 

 closely allied to S. Sarsii Smith (Trans. Conn. Acad., V. p. 59, PL II. figs. 6-8, 

 1879) than to septemcarinata; the elongated and acute rostrum, the prominent 

 dentation of the carapax and abdomen, and the structure of the telson in Sardi, 

 show a marked approach toward the princeps, although the two species are very 

 different in general appearance. 



Sabinea hystrix (Paracrangon hystrix A. Milne-Edwards, Ann. Sci. Nat., 6 me 

 serie, XL No. 4, p. 6, 1881), from 730 fath., near Guadaloupe, is very closely 

 allied and probably identical with this species, which, though externally some- 

 what like Paracrangon ecliinatus Dana, differs essentially in several structural 

 features in which, as pointed out above, it agrees with the typical species of 

 Sabinea. In Paracrangon ecliinatus, not only are the second pair of legs com- 

 pletely obsolete, but there are no arthrobranchise, the branchial formula being 

 the same as for Ceraphilus boreas and Agassizii. 



RHACHOCARIN^l, subfam. nov. 



Anterior thoracic legs stout, non-chelate ; second pair slender, chelate, and 

 with multiarticulate carpi ; coxae of the external maxillipeds articulated with 

 the adjacent edge of the carapax. 



These characters sufficiently distinguish this subfamily from all other Cran- 

 gonidse. The broad, ovate antennal scales with both margins ciliated are prob- 

 ably also characteristic of the subfamily, which, as far as known to me, contains 

 but one genus. 



RHACHOCARIS,* gen. nov. 

 Plates V. and VI. 



The carapax is subcylindrical, carinated longitudinally, rostrated, with 

 prominent antero-lateral and antennal spines, and the margins of the branchi- 

 ostegites are strongly incurved opposite the bases of the second pair of legs 

 and are connected each side with the coxa? of the external maxillipeds by two 

 processes from the coxa interlocking between their converging tips a projection 

 in the margin of the carapax so as to form therewith an articulation admitting 

 slight motion. 



The eyes are large and pyriform, with the cornea expanded and very large. 

 The antennulee are very nearly as in Crangon. The antennal scale is broad, 



* 'Pdxts and napls. 



