484 



THE VOYAGE OF H.M.S. CHALLENGER. 



Crangon vulgaris, Fabricius. 



Crangon vulgaris, Fabricius, Suppl. Entom. Syst., p. 410. 



Dorsal surface of the posterior somites of the pleon rounded, without a carina. 



Telson not channelled. 



Length 52 mm. (2 in.). 



Habitat. — Off Yokoska, Japan ; in from 5 to 20 fathoms. 



There are three specimens in the collection that correspond very closely with the 

 European species ; one male, one female, one young. 



They have no channel on the telson nor a carina on the pleon, but the former is slender 

 and a little larger than the lateral plates — in which point alone they differ from the 

 European type, which has the telson shorter and thicker, and corresponds with those that 

 I take to be Crangon affinis, de Haan. 



The following are the measurements of the Japanese forms as compared with the 

 British species, and it appears to me difficult to consider them otherwise than as slight 

 variations of the same species : — 



Crangon affinis, de Haan (PI. LXXX VI. figs. 1-3). 



Crangon affinis, de Haan, Crust, in v. Siebold, Fauna Japonica, p. 182. 



Crangon propinquus, Stimpson, Proc. Acad. Nat. Sci. Philad., p. 94, December 1858. 



Dorsal surface smooth, carapace nearly one-third the length of the animal, measured 

 from the base of the rostrum to the base of the telson. Anterior margin furnished with 

 a small, blunt, flattened, dorsally concave rostrum, that scarcely reaches to the extremity 

 of the ophthalmopoda, with a small tooth at the outer angle of the orbital notch 

 and another more advanced on the outer side of the second pair of antennae. 



