DIASTOPORIDiE. 117 



Norway and Finmark/ (' Annals N. H.,' 2 ser. xviii, p. 35.) It will be found of great 

 convenience in the primary distinction of species. 



The subdivisions of the genus may consequently be thus synoptically expressed -. 



(a) Solitarise. 



a. PedunculatcB. 



1. Interspaces smooth. 



2. Interspaces porous. 



/3. Sessile. 



1. Interspaces smooth. 



2. Interspaces porous. 



{b) Sociales. 



a. GloboscB. 



1. Interspaces smooth. 



2. Interspaces porous. 



/3. CrustacecB. 



1. Interspaces smooth. 



2. Interspaces porous. 



{a). SoLlTARIiE. 



a. Pedunculata. 1. Interspaces smooth. 



1. D. STRIATULA, {71. SJJ.) PI. XVII, fig. 5. 



Stipitata. Superficie disci inferiori stipisque glabra, integra, lineis parallelis, longi- 

 tudinalibus delicatulis, ornata, obscure annulata. 



Under surface of disc and surface of peduncle smooth, imperforate, marked with 

 delicate, parallel longitudinal lines, and faintly annulated. 



Habitat. — C. Crag, Sutton ; S. Wood. 



In some conditions of the recent D. truncata (so termed) inhabiting the Northern Seas 

 in deep water, a superficial inspection might confound that species with the present, though 

 very little closer observation will show that the two are quite distinct. In the so termed 

 D. truncata, of which figures will be found in the paper above referred to on the Norway 

 Polyzoaj the surface between the costas, and the outer surface of the entire growth are like a 

 honeycomb, and the tubes connate quite to the mouth, whilst in D. striatula a considerable 



