10 U.S. NATIONAL MUSEU]\1 BULLETIN 2 78 



into triangular projection. Dorsal surface of pereonite 3 with pair 

 of anterior spines, sometimes reduced to small humps, pair of mid- 

 posterior spines, and single posterior spine; anterolateral margin 

 produced as in pereonite 2; lateral margin of pleura with anterior 

 and posterior spines and spine above giUs in males, females without 

 posterior spine. Pereonite 4 similar to pereonite 3 in males, females 

 without dorsal anterior spine. Dorsal surface of pereonite 5 similar 

 to pereonite 3, pleura mth only anterior spine and dorsally directed 

 spine at base of pereopod 5. Pereonite 7 with dorsally directed spine 

 at base of pereopod 7. Length of largest male 20 mm, female 16 mm. 

 Setal formula for terminal article of mandibular palp 1-10-1 to 

 1-12-1. Left mandible with 5-toothed incisor, 5-toothed lacinia 

 mobilis, setal row of 3 serrate setae, molar with plumose seta. Right 

 mandible with 5-toothed incisor, lacinia mobilis serrate on cutting 

 margin, setal row of 2 serrate setae, molar with plumose seta. Palp 

 of maxilla 1 usually with 5 robust apical spines and several setae; 

 outer lobe \vith 7 apical spines, usually bifid but sometimes more 

 branches with increase in size of individual. Inner and outer lobes 

 of maxilla 2 quite setose on apical margin and spines occasionally 

 present. Outer lobe of maxilliped with 2 apical setae, 1 long apical 

 spine, and up to 12 smaller marginal spines; inner lobe mth 2 small 

 spines and up to 12 apical setae, as many as 9 of which plumose; 

 palp similar to that of Ca/preUa. 



Propodus of gnathopod 1 triangular with 2 proximal grasping 

 spines, grasping margin not distinctly serrate; grasping margin of 

 dactylus serrate, particularly at tip. Propodus of gnathopod 2 quite 

 robust, palm heavily setose with small proximal tooth, anterior margin 

 with distal projection; dactylus not serrate. 



Gills subeUiptical. 



Pereopods 3 and 4 absent. Pereopods 5-7, 6-segmented, palm of 

 propodus with pair of proximal grasping spines. 



Abdomen of male and female wdth 1 pair of appendages and pair 

 of setose lobes; in male appendage placed on raised projection and 

 uniarticulate; in female, appendage neither on projection nor 

 articulated. 



Variation. — This species appears to be quite constant in body 

 spination vnih. the exception of the first pair of spines on the dorsal 

 surface of pereonite 4. These may be present as fully developed 

 spines or as only small humps. 



Distribution. — Type-locahty : Haugesund, Norway. 



Other records: Miu-man coast to Haugesund on the Norwegian 

 coast, Spitsbergen, Faeroe Islands, Iceland, east and west coasts 

 of Greenland. 



