CRl'STACRA MAI.ACOSTRACA III. 



Tin- front area between the basal joints of the antennuUc is rather narrow, longitudinally con- 

 e with the lateral margins raised (fig. a b) and it tapers strongly forwards, but instead of being 

 horizontal as in E. contttta or . HansrMi its anterior part, seen somewhat from the side, slope* down- 

 wards and terminates below without being well marked off from the front just above the vaulted 

 clyjM First joint of the antennulae (fig. 2 c) shaped as in E. rornu/a, especially as the antero-iuterior 



lobe is somewhat short, considerably broader than long; second joint inserted and shaped as in E. cor- 

 MH/a, considerably thicker in the male than in the female, a little or somewhat shorter than the more 

 slender third joint - Antennal squama (fig. a d) oblong-triangular, terminating in a spine, and slightly 

 more than half as long as the breadth of third joint -- Maxillipeds (fig. a e) have the second joint, 

 counted to the articulation of third joint, half as long again as broad (in this respect it agrees with 

 . corHuta, as Sars has figured the second joint too short); the distal terminal corner of the epipod 

 more rounded than in E, cornuta. 



Thoracic segments (fig. a a) nearly as in E. cornuta, the epimera a little more produced than 

 in that specfafc 



The female abdominal operculum very different from that in E. cornttta. Seen from be-low (fig. 

 a k) it is broadest much before the middle, and then the most lateral part at each side constitutes a 

 rounded rather short lobe directed outwards; the great portion of the operculum behind these lobes 

 is triangular with each lateral margin a little sinuate and the end narrowly rounded; the surface has 

 a high keel from somewhat from the base to near the posterior end. Seen from the side (fig. a i) the 

 operculum is highly vaulted ; its lower margin is bent, forming an angle of about 100, which is placed so 

 far backwards as the insertions of the uropods; the lower margin in front of that angle is long and 

 straight, and behind the angle it is somewhat short and almost vertical on the lower surface of the 

 abdomen. - The male abdominal operculum also differs much from that in E. cornuta. Its median 

 lamella (fig. a f) is narrower, about three times as long as broad and more constricted near the middle; 

 the terminal part of each pleopod forms a lobe (fig. a g), which is conspicuously longer than broad, 

 with setse along its somewhat convex outer margin and the rather narrowly rounded end; at the 

 outer base of the lobe the pleopod is suddenly a little broader, so that a small and low, rectangular 

 and protruding part is observed. Each lateral plate (fig. 2 h) has a kind of low but very broad, rounded 

 lobe on the basal part at the outer margin, and this lobe has some marginal hairs; the distal half of 

 the outer margin is considerably concave, and the terminal part of the plate is produced into a lobe 

 as long as broad, with both margins concave and the end narrow with a few setae; the copulatory 

 organ has its second joint rather short, only a little more than half as long as the plate, and the part 

 containing vesicle and duct is only somewhat longer than the part from base to vesicle; the distal part of 

 the inner margin, which runs across the coupling hook, is more concave than in E. cornuta. - - Uropods 

 (fig. a 1) with the peduncle thick, the endopod considerably longer and much thicker than the endopod. 



Length of large males from the cold area 99-3 mm., of females 911-5 mm., but the two 

 largest females, both from the "Ingolf" Stat 103, have no marsupium and are ii-a and 11-5 mm. long. 

 The length of adult specimens from the warm area 5-5 to 7 mm. 



Remarks. E. inermis is abundantly distinguished from E. cornufa by having the anterior 

 part of the front area curved downwards and without any freely protruding end, by the unequal length 



