83 



species, and composed of from 8 to 10 articulations. Legs moderately strong. 

 Stylet of 2nd pair of pleopoda in male reaching somewhat beyond the inner plate. 

 Uropoda with the terminal plate obliquely roiyided at the tip. Colour uniformly 

 light reddish blown. Length of adult female 11 mm., of male 15 mm. 



jRewto'l'*. This form briefly described, but not figured, by Rathke under 

 the above name, has generally been regarded as only a variety of 1. lialiica. 

 It is certainly, however, a well-defined species, differing, as it does, from the 

 type species not only in the far inferior size, but also in several anatomical 

 details mentioned in the above diagnosis. It is best recognized by the narrow, 

 lanceolate form of the terminal segment of the metasome, which is perfectly con- 

 stant in all specimens. 



Occurrence. Rathke found this form at Christiansund and Trondhjem. 

 I have myself occasionally met with it on the sandy beach of Listerland, and in 

 the outer part of the Christiania Fjord, where it occurred in quite shallow water. 

 Out of Norway it has not yet been recorded. 



4 Idothea viridis (Slabber), 



(PI. XXXIV. fig. 2.) 

 Oniscus viridis, Slabber, Naturk. verlustigingen, p. 104, PL XII, figs 4 5. 



Syn: Idotca pliosplwrea, Hoek (not Harger). 



Specific Characters. Body very slender, oblong linear in form, more than 

 4 times as long us it is broad; that of male, as usual, still more slender than in the 

 female. Cephalon but little broader than it is long, frontal margin slightly concaved. 

 Coxal plates comparatively small, not contiguous. Metasome occupying about V 3 

 of the length of the body, last segment but very slightly narrowed distally. and 

 terminating in a comparatively short and obtuse median prominence, lateral cor- 

 ners distinct, though obtuse. Eyes of moderate size. Superior antenna 1 nearly 

 as in /. granulosa ; inferior antenna^, on the other hand, comparatively more 

 slender, reaching beyond the 2nd segment of mesosome, flagellum exceeding the 

 peduncle in length, and composed of from 10 to 15 articulations. Legs more 

 slender than in most other species, though, as usual, somewhat stronger in male 

 than in female. Stylet of 2nd pair of pleopoda in male extending considerably 

 beyond the inner plate. Uropoda with the terminal piece obtusely truncated at the 

 tip. Colour uniformly greenish. Length of adult female lo mm., of male 12 mm. 



lu'warf.*. The 2 detail-figures (PI. VII, figs 2, 2 r) given by Dr. Hoek 

 in the 2nd part of his "Crustacea Neerlandica' 1 ') leave no doubt that the form 



l ) Tijdsdir. Nederl, Dierk. Vereyniging. 2 series, Vol. 2, P;sr( .'!, 



