613 



liasal lobe subobsolete; 2nd pair witli tlie outer lobe larger than the inner. 

 Maxillipeds sublatnellar, basal lobes narrowly produced, masticatory lol)es 

 long and narrow, with the inner edge fringed with slender spines, palp com- 

 paratively slender, with the last joint rather small, dactylus short and 

 setous at the tip. Gnathopoda of the very same structure in the two sexes; 

 the anterior ones rather slender, with the ischial joint forming below a 

 rounded, densely setous expansion, carpus much elongated and densely setous 

 below, propodos narrow, and having a distinctly defined, though very short 

 palm. Posterior gnathopoda somewhat stronger than the anterior, meral joint 

 forming a broad lamellar expansion, firmly connected with the lower side of 

 the carpus, and edged with a double row of extremely elongated and finelj' 

 ciliated setae curving anteriorly, propodos subliuear, without any distinctly 

 defined palm. The 2 anterior pairs of pereiopoda with the basal joint large 

 and broad, and the meral joint more or less expanded. The 2 succeeding 

 pairs comparatively stout and of same structure, both having the meral joint 

 cibliquely expanded in front, and the carpal one armed outside with 2 oblique 

 rows of strong spines, dactylus short and inverted. Last pair of pereiopoda 

 rather elongated and slender, with the basal joint lamellarly expanded and 

 densely fringed on both edges with long, ciliated setae. Branchial lamellae 

 well developed, wanting at the base of the posterior gnathopoda; incubatory 

 lamellae narrow, but edged with strong setae. Pleopoda with the basal part 

 greatly expanded inside. The 2 anterior pairs of uropoda with the rami 

 comparatively short, and coarsely spinoiis outside; jlast pair with the basal 

 joint scarcely expanded, terminal joint lamellar, setiferous. Telson small and 

 distinctly defined from the last segment. 



Bemarks. — The present genus, established as early as in the year 

 1817 by Latreille, is easily recognizable by the comparatively stout and 

 depressed body, the very strongly-built, pediform inferior antennae, and the 

 peculiar structure of the gnathopoda. The gejius' comprises several species 

 both from the northern and southern hemispheres, and I have recently had 

 an occasion of .stating, that also in the Caspian Sea it is represented by a 

 number of well marked species. To the fauna of Norway belong 4 species, 

 to be described below. 



81 — Crustacea. 



