Manchester Memoirs, Vol. Ixii, (191 7) No. 4 9 



zooid the total length of one of the filaments was 0.672 m.m. and of 

 this a length of 0.192 m.m. projected beyond the coelenteric cavity. 

 In all the siphonozooids of this specimen the filaments were fully 

 extended and showed no convolutions or coils : seen from the 

 external surface of the colony they curved out from the base of the 

 stomodaeum, the two filaments forming- an angle of from 45 

 -90 degrees. 



C. pusilla, Herklots. 



In describing this species under the name Stylobelemnon, 

 Kolliker states that the siphonozooids have two mesenteric fila- 

 ments. Recent writers however cast doubt on this observation : 

 ". . . . auch Mesenterialfilamente vermochte ich meist nicht 

 wahrzunehmen. Nach Kolliker (1872 p. 350) sllen zwei Mesen- 

 terialfilamente vorhanden sein, doch reichte der Erhaltungszustand 

 meines Materials nicht aus, um iiberall mit Sicherheit das 

 Vorkommen dieser beiden, jedenfalls den dorsalen Septen 

 zugehorigen Filamente wiederzufinden. Nur an ein paar Stellen 

 habe ich diese dorsalen Mesenterialfilamente erkennen konnen'' 

 (K. and B. 1911 p. 513). As I have had no opportunity of examin- 

 ing this species I am unable to add anything further to these 

 statements. 



Actinoptilum molle, Kiikenthal. 



This species is closely allied to the Cavernularias and similarly 

 possesses well developed dorsal mesenteric filaments. 



Echinoptilum echinatum, Kiikenthal and Broch. 



A specimen dredged by the "Valdivia" off Somaliland is describ- 

 ed as having siphonozooids with straight powerfully developed 

 dorsal septa bearing filaments (K. and B. p. 518). 



E. elongatum, Hickson. 



The filaments in this species are the longest observed in the 

 genus and reach a length of 0.288 m.m. 



E. minimum, Hickson. 



Mesenteric filaments short: 0.16 - 0.18 m.m. in length and aver- 

 age width 0.037 m.m. 



E. roseum, Hickson. 



The filaments are narrow and only reach down for a distance 

 equal to the length of the stomodaeum. As in the other species of 

 the genera they are straight. E. roseum, E. elongatum and E. 

 minimum are new species taken by the "Siboga" in the East 

 Indian Archipelago. 



