40 



16. Euchaeta glaeialis, Hansen. 



(PI. XXVII). 



Euchceta glatialis, Hansen. Oversigt over cle paa Dijmplma-Togtet indsamlede Krebsdyr, 

 p. 74, PI. XXIII, figs. 5 5K, PI. XIV, figs. 1 Id. 



Syn: Euchceta norvegica, G. 0. gars (part). 



Specific Characters. Female. Very like the preceding species in its external 

 appearance, though of larger size and somewhat more robust form of body. Ce- 

 phalosome not defined from the 1st pedigerous segment by any perceptible 

 demarcation, form of rostrum as in E. norvegica. Lateral lobes of last segment 

 of metasome slightly angular, but without any tuberculiform projection at the tip. 

 Urosome comparatively shorter, not nearly attaining half the length of the anterior 

 division, genital protuberance issuing from about the middle of the segment, and 

 broadly conical in form, extending somewhat obliquely behind, tip provided on 

 each side with 2 narrowly rounded lobules. Outer caudal segments minutely 

 hairy. Caudal rami comparatively shorter than in E. norvegica and less oblique, 

 appendicular bristle not exceeding in length the marginal setae, and slightly 

 flexuous at the base, the innermost but one of the caudal setae almost twice the 

 length of the others. Structure of the several appendages almost exactly as in 

 E. norvegica. 



Male likewise closely resembling that of the said species, though perhaps 

 somewhat less slender of form, and differing in the structure of the hand of the 

 last left leg, the thumb of which has the form of an oblong quadrangular plate 

 closely crenulated along the edges, and transversely truncated at the tip. 



Colour more or less bright red. 



Length of adult female about 10 mm., of male 8 mm. 



RemarTcs. This form was first described by Dr. Hansen in the above- 

 quoted paper. I did not, however, at first recognise its specific difference from 

 E. norvegica, and it was therefore, in my account of the Crustacea of Nansen's 

 Polar Expedition, only quoted as a synonym to that species. The closer examina- 

 tion which I have recently instituted, however, has led to the result, that Dr. 

 Hansen's species ought to be maintained, though it certainly comes very near to 

 E. norvegica. The chief differences consist in the somewhat more robust form of 

 the body, the more conical genital protuberance in the female, and the rather 

 different structure of the thumb in the left last leg of the male. It also attains a 

 considerably larger size, some of the specimens even exceeding 10 mm. in length. 



Occurrence. In the immediate neighbourhood of the Norwegian coast 

 this form has not yet been met with, I have, however, recently found it in 3 



