39G MONOCAULUS GLACIALIS. 



tentacles longer than the distal, and disposed in a single verticil near the base of the 

 hydranth, the distal set scattered over a zone close to the summit of the hydranth. 



GONOSOME. — Sporosacs borne upon peduncles, which spring from the body of 

 the hydranth between the proximal and distal sets of tentacles. 



The genus Monocaulus is constituted for the Corpnorpha yhickdis of Sars, a form which, 

 though its trophosonie is that of a Corymorpha, is yet strongly distinguished from the true Cory- 

 morphas by its adeloconic gonophores. 



The description given by Agassiz of his Corpnorpha pendula renders it necessary to place this 

 hydroid also in the genus Monocaulus. 



*^* 1. Monocaulus glacialis, Sars. 



CoRYMORPHA GLACIALIS, — Suvs, Forhaiidl. i Vid. Selsk. i Cliristiania, 1859; trans, in Wieg. 



Arch., 1860, p. 341 ; and in Ann. Nat. Hist., 1861, p. 353. 

 Monocaulus glacialis, — Allman, in Ann. Nat. Hist, for May, 1864. 



TROPHOSOME. — nmROCAULUs attaining a height of four or five inches. 

 Proximal tentacles of htdeanth very long, forty to fifty in number ; distal tentacles 

 very short and very numerous. 



GONOSOME. — Peduncles of gonophoiies thirty to thirty-five, but slightly 

 branched. Sporosacs oval, destitute of tentaculiform appendage. 



Habitat. — On a soft clayey and stony sea bottom. 

 Bathpnetrical distribution. — Deep sea, from 60 to 120 fathoms. 

 Locality. — The Varangerfjord, near Nadsoe, Sars. 



The only account we possess of Monocaulus glacicdis is Sars's short description, from which 

 the above diagnosis has been compiled, and which is by no means so full as could be desired. 

 Sars's specimens were obtained in small quantity at a depth of from 60 to SO fathoms, and rather 

 abundantly at a depth of from 80 to 120 fathoms. The only locality where it has as yet been 

 found lies as far north as 70° N. lat. It thus possesses special interest, not only from the depth 

 at which it lies, but from its very high northern latitude. 



Prevailing colour a clear bright pink. 



