84 



he records as I. phosphorea Harger is the very same species as that here treated 

 of. It can scarcely be identical with the North American species, whereas it is 

 most likely that Dr. Hoek is light in considering the Oniscus virhlis of Slabber 

 to be the same species. In any case, the specific name proposed by Slabber ought to 

 be retained as the much older one. Before becoming acquainted with Dr. Hoek's 

 paper I had named this form I. angusta, owing to its unusually narrow form of 

 body, and it is so named in the plate. From the other Norwegian Idothese it is 

 at once recognized by its slender form, which approaches to that in the genus 

 Stenosoma. The manner in which the last segment of the metasome terminates, 

 somewhat resembles that in I. bdltica, there being traces of a tridentate shape; 

 but the -median prominence is considerably shorter and blunter, and the lateral 

 corners very obtuse. 



Occurrence. — I have taken this form rather plentifully in the Christiania 

 Fjord, at Moss, in cpiite shallow water among eel-grass. 



Distribution. — Dutch coast (Hoek), coast of France (Hoek). 



5. Idothea negleeta, G. 0. Sars, n. sp. 



(PI. XXXV, fig. 1.) 



Specific Characters. — Body oblong oval in form, scarcely 3 times as long 

 as it is broad, and, as usual, comparatively shorter and stouter in female than 

 in male, with the greatest width farther forward. Cephalon about twice as broad 

 as it is long, frontal margin straight. Coxal plates in female not very large, and 

 scarcely contiguous, in male much more fully developed, and forming together on 

 each side, as in I. baltica, a broad marginal area. Metasome exceeding 1 / 3 of 

 the length of the body, last segment but slightly narrowed distally, and termina- 

 ting in a blunt point, lateral corners obsolete. Eyes rather large. Superior an- 

 tennae with the last joint of the peduncle longer than the 2nd. Inferior antennnse 

 rather slender, reaching to the end of the 2nd segment of mesosome, flag ell um 

 much longer than the peduncle, and composed of from 16 to 20 articulations. 

 Legs moderately strong. Stylet of 2nd pair of pleopoda in male very short, not 

 reaching far beyond the middle of the inner plate. Uropoda with the terminal 

 piece transversely truncated. Colour generally very dark brown or almost black, 

 sometimes lighter, variegated with small, irregular patches. Length of adult 

 female 16 mm., of male 25 mm. 



Remarks. — There cannot be any doubt that this very common form must have 

 been observed by several authors. It has, however, not yet been recognized as a 

 distinct species, but has either been regarded as merely a variety of I. baltica, 



