232 MR. Gt. BUSK ON THE POLYZOA 



S. scabra. In other respects, however, the resemblance between 

 the northern and southern forms is extremely close. 



Genus Menipea, Lamx. 

 1. Menipea gracilis, mihi. 



Char. — Zocecia much elongated, subtubular downwards ; aper- 

 ture oval, border slightly thickened ; usually a single spine on the 

 outer side above and occasionally one on the inner ; a broad arched, 

 gibbous, entire operculum ; anterior avicularium small, rare, and 

 only (?) on the median zooecium at a bifurcation. Median zoce- 

 cium not mucronate ; five to uine cells in an internode. Polypide 

 with 12 tentacles. 



Cellularia ternata (forma gracilis), Smitt, I. c. 1867, pp. 283-310, pi. xvi. 

 figs. 17, 18, 19, 20, 23, 24 (non 21, 22), (excl. syn.). 



Sab. Franklin-Pierce Bay, 79° 29' N. lat., 13-15 fras. (S. W. _F.); 

 Spitzbergen, 200 fms. (Smitt). 



The differences between this form of Menipea and the well- 

 known typical M. ternata appear to me to be so obvious that I 

 am quite unable to agree with Professor Smitt in considering them 

 merely in the light of varieties, i. e. if we are to understand that 

 his "forrna" is equivalent to " variety '." 



The points to which I would advert as affording sufficient marks 

 of distinction are : — 



1. The greater number of zocecia in each internode. 



2. The marginal spines being limited at most to two unjointed 

 ones. 



3. The much greater expansion of the operculum. 



4. The absence of a mucronate spine at the summit of the 

 median cell at a bifurcation, whilst in M. ternata there is always an 

 articulated spine or mucro in that situation and very often two. 



Amongst the synonyms of his " forma gracilis" Prof. Smitt 

 gives my Menipea arctica. But upon again referring to the ori- 

 ginal type specimen of that species from Dr. Wallich's collection, 

 procured in Hamilton's Inlet, Labrador, 15 fms., the differences 

 appear to be quite as great as those which exist between M. gra- 

 cilis and M. ternata. The general habit is altogether different, 

 and in M. arctica there is not the vestige of an operculum ; and the 

 median cell is mucronate, the mucro, how ever, not being articulated 

 as it usually is in M. ternata. 



