92 



Occurrence. — It would seem to be a very rare species. The first specimen 

 was found by the present author on the Storeggen bank, clinging to a spine of 

 Echinus rarispinus G. 0. Sars, taken up from a depth of 80 to 100 fathoms. 

 Another specimen was taken off the Lofoten Islands in about the same depth. 



Distribution. — Skagerak (Meinert). 



Gen. 2. ArctUTella, G. O. Sars, n. 



Generic Characters. — Body less elongated than in Astacilla, and in female, 

 slightly depressed, the middle segment being very large and broad, scutiform. 

 Metasome about as in Astacilla. Superior antennae with only a very restricted 

 number of olfactory filaments issuing from the tip of the flagellum. Inferior an- 

 tennae of no considerable length, flagellum 3-articulate and terminating in a 

 long spine. Maxillipeds with the palp rather slender, 5-articulate, epignath very 

 large and ciliated at the tip. 1st pair of legs with the proximal part of the 

 dactylus narrow, linear; the 3 succeeding pairs less elongated than in Astacilla, 

 and less richly supplied with setae. Incubatory pouch confined to the middle seg- 

 ment of mesosome. Male much smaller than female, and having the middle seg- 

 ment of mesosome simple, cylindric in form. 



Remarks. — This new genus is founded upon the peculiar form described 

 by the present author as Astacilla, dilatata. A closer examination of this form 

 has shown it also to differ from the species of the genus Astacilla in some ana- 

 tomical details mentioned in the above diagnosis, so that it should more properly' 

 be regarded as the type of a distinct, though nearly-allied genus. 



Areturella dilatata, G. 0. Sars. 



(El. XXXVIII.) 

 Astacilla dilatata, G. 0. Sars, Oversigt af Norges Crustaceer I, p. 63, PI. 2, fig. 3. 



Specific Characters. — Body of female very tubercular, some of the tu- 

 bercles assuming a spiniform character. Cephalon with 2 dorsal juxtaposed, and 

 somewhat procurved pyramidal prominences, in front of which occur several smaller 

 tubercles. Each of the 3 succeeding segments with a transverse series of 5 co- 

 nical tubercles, the median one being the most prominent, lateral parts triangu- 

 larly produced, those of 1st segment larger and deeper than those of the 2 other 

 segments. Middle segment of mesosome exceedingly large and broad, somewhat 



