42 



Gen. 3. Doropygus, Thorell, 1859. 



Generic Characters. Body in female distinctly compressed, and exhibiting 

 a pronounced ventral curvature; that in male more cylindrical in shape, and 

 gradually tapered behind. Incubatory pouch very large and gibbously pro- 

 minent behind. Tail narrow cylindric in form, and more or less abruptly bent 

 downwards, last segment deeply cleft behind. Caudal rami more or less 

 produced, narrowed distally, and only provided with very small rudiments of 

 setae. Anterior antennae of the very same structure in the 2 sexes, being 

 composed of 8 or 9 joints, the first 2 of which are very broad and com- 

 pressed. Posterior antennae scarcely shorter than the anterior, but much 

 narrower, and highly chitinised, tapering distally, and armed at the tip with 

 an apparently immobile claw. Mandibular palp with the outer ramus well 

 developed, narrowly exerted at the end, and divided into 4 more or less 

 distinctly defined joints. Endopodal part of maxillae with a distinctly defined 

 terminal joint. Anterior maxillipeds with the terminal part bi-or 3-articulate. 

 Posterior maxillipeds more or less reduced. The 4 anterior pairs of legs with 

 the basal part very thick and muscular, rami generally 3-articulate and of 

 equal size. Last pair of legs with the proximal joint sub-quadrangular in form 

 and not produced outside to any distinctly defined process, distal joint more 

 or less slender, sub-linear in shape. 



Remarks. The present genus, being that established at the earliest date, 

 must of course be regarded as the type of the family Doropygidce. It is here 

 taken in a more restricted sense than done by Thorell and most other authors, 

 some of the species referred by them to this genus having turned out to 

 represent types of nearly allied genera. In the. restriction here adopted, the 

 genus as yet comprises 6 species, 3 of which have been found on the Nor- 

 wegian coast and will be described below. 



9. Doropygus pulex, Thorell. 



(PI. XX). 



Doropygus pulex, Thorell, 1. c. p. 46, PI. VI, 8. 

 Syn: Doropygus pullus, Buchholtz. 



Specific Characters. Female. Body comparatively short and stout, with 

 the anterior division, seen laterally, oblong oval in form and somewhat wide- 

 ning distally. Incubatory pouch gently curved and greatly prominent behind, 

 its posterior part being somewhat exerted and narrowly rounded at the end. 



