— 33 - 



the distal half of the margin. The dorsal process on third 

 abdominal segment sjender, spiniform, compressed, about 

 one-third as long as the next segment. Copulatory organs 

 somewhat reminding of those in E. Sibogœ, but differing 

 in some features ; the terminal process has the keel shorter 

 and more curved, the main part longer and more slender; 

 the proximal process has the end rounded ; the lateral 

 process distally with a tooth as in E. Sibogœ and E. di- 

 stinguenda. — Length 7.5-1 0.8 - nm . 



The tropical East Pacific, where it is rather common 

 (Agassiz Exp.). 



The species is easily separated from all other forms by 

 the curious, large and movable lamella from second antenr 

 nular joint. 



E. gibboides Ortm. — The rostrum is rather long with 

 its distal part spiniform ; the eyes large. First antennular 

 joint distally considerably raised above with a moderately 

 long lobe directed forwards and somewhat upwards and 

 beyond the middle abruptly bent much outwards, its ter- 

 minal part being an oblong, acute triangle. Second joint 

 distally with the upper wall produced as a kind of short 

 lobe covering the basal part of third joint excepting near 

 the outer margin, and the anterior margin of this lobe is 

 distinctly concave and its outer angle right. Third joint 

 with a high and long dorsal keel ; the terminal margin of 

 this keel is very oblique and incised above, while the upper 

 angle is produced in a spine. Third abdominal segment 

 with the dorsal process short. The copulatory organs 

 differ in several features from those in the preceding 

 species, but special mention is scarcely needed, as the 

 characters enumerated may be sufficient. — Length of a 

 large male 22 mm , of a very large female 27 mm . 



Temperate and tropical North Atlantic and tropical 

 East Pacific. 



E. mucronata G. O. S. — The very short frontal plate 

 produced in a very short, proportionately very broad and 

 badly defined rostrum terminating in an obtuse angle. 



(210) 



