406 DE. J. G. DE MAN ON CEUSTACEA CHIEFLY 



carapace and the tip of the anteniial scales ; the process on the outer side of the hase 

 is rather narrow and does not quite reach to the distal end of the first joint, hardly 

 exceeding the eye-peduncles when they are turned straight forward. The gradually 

 tapering, inner flagellum, which surpasses somewhat the antennal scales, is a little longer 

 than the peduncle, measured from the orhital margin of the carapace ; the outer flagellum 

 reaches to the end of the blade. 



The external antenna? are just as long as the body. The scale (PI. 31. fig. 18), measured 

 along its straight outer margin, appears to be four-fifths the length of the carapace, 

 exclusive of the rostrum ; it resembles that of Crcmgon alashensis, but it is only three 

 times as long as broad; the end of the blade is rounded, not produced at the antero- 

 intemal angle, and much broader than the spine at this level ; the spine extends almost 

 as much beyond the blade as the end of the latter is broad. The antennal peduncle 

 extends as far forward as the penultimate joint of the external maxillipeds, which just 

 reach to the end of the blade. 



The first pair of feet (fig. 19) are somewhat shorter than the antennal scales, reaching 

 a little beyond the antennal peduncles. The chelae, which are 5'6 mm. long and 1"5 mm. 

 broad at the base of the spinous pollex, are a little slenderer than those of Or. alaskensis, 

 for they are almost four times as long as broad ; the obliquity of the terminal margin is 

 in both species the same. 



The legs of the fifth pair reach as far forward as those of the first. 



There is a slender spine on the sternum between the third pair of legs. 



The single typical specimen of Ortmann's Crangon affinis from Maizuru, Japan, which is 

 lying before me (Ortmann, I. c), seems to belong to this species ; the rostrum is, however, 

 a little longer and the process on the outer side of the base of the antennular peduncle 

 reaches almost to the end of the first joint. Ortmann's specimen carries a Bopyrid on 

 the left side of the carapace. 



Crangon affinis, de Haan, is certainly diff'erent. In this species, indeed, the external 

 maxillipeds are longer than the antennal scales, and the latter are just as long as the 

 carapace, the rostrum excluded. Nothing is said about the carination of the fifth 

 abdominal segment. Unfortunately de Haan's types do not now exist in the Leyden 

 Museum. 



Crangon propinquus, Stimpson, differs by the third and the fourth segments being 

 carinate, not the fifth. According to Miss Rathbun *, the rostrum of this species should 

 exceed the eyes. 



Crangon cassiope, de Man. (PI. 32. figs. 20-25.) 



Crangon cassiope, de Man, in Ann. & Mag. Nat. Hist. ser. 7, vol. xvii. 1906, p. 402. 



Two egg-laden females from the Inland Sea of Japan, captured in deep water, common 

 on mud. 



In its outer appearance Crangon cassiope much resembles the typical species of this 

 genus, viz. Crangon vulgaris, but it is at once distinguished by the sixth segment of 

 the abdomen, which is convex, not sidcate, beneath. This species appears therefore also 



* Rathbun, in Proc. U.S. Nat. Mus. xxvi. 1002, p. 42. 



