452 HYDROID ZOOPHYTES COLLECTED BY DR WILLEY IN THE SOUTHERX SEAS. 



The position of the gonophore, rising from the side of the cup of the hydrotheca, instead 

 of from the stolon and within a cup of its own, is the only marked difference which 

 makes it necessary to separate the species. 



Locality. Blanche Bay, New Britain ; growing among other zooph}i:es attached 

 to ropes and ti.sh-ba.skets down to 40 fathoms. 



Gexus. Bougainvillia, Lesson. 



Bougainvillia muscus Allman, PI. XLIV. Figs. 2, 2 a, 2 b. 



There are colonies of this Bougainvillia covering the cast spines of a Cidaris. They 

 are taller than the description of B. muscus, as described by Hincks', corresponding 

 thus more with his form intermediate between that species and B. rainosa, but they have 

 not the compound stem of this form though they have the sanded polyparj-. 



These colonies have gonophores (Fig. 2 h) borne on the stem, some way below the 

 polypites, two or three together on a branched offshoot. 



From a separate collection taken from ropes and fish-baskets and floats there 

 are also some colonies which are shorter and have curious tendrils, some simple, some 

 branched (Fig. 2 a), and of varjang lengths, attached to the stems below the poh'pites. 



The characters in both these sets of specimens do not seem sufficiently marked to 

 justify the formation of a species apart from Bougainvillia muscus Allman. 



Locality. Blanche Bay, New Britain. 



Family. Tubulakiid^, Hincks. 

 Genus. Ectopleura, L. Agassiz. 



Ectopleura pacifica, n. sp., PI. XLIV. Figs. 1, 1 a. 



Of this fine species there are a profusion of colonies, detached from floats, fish- 

 baskets, &c. The stems are simple, unringed, diminishing in width towards the base 

 and about 2 cm. high, rising from a creeping stolon which connects the colony. There 

 are some processes given off fiom the stem near the base in many of the specimens 

 which probably help to attach the colonies to the objects thej" gi-ow upon. The 

 polypite is abruptly marked off from the supporting stalk. The tentacles are disposed 

 in two verticils of from 18 — 20 each. The distal tentacles appear to be not wholly 

 filiform (see Fig. 1), but this may be the effect of contraction of the preserved specimen. 



The gonophores are borne in clusters of from seven to nine on branched peduncles 

 which spring from the body of the polypite, between the two sets of tentacles. The 

 most highly developed among them have two long tentacles (Fig. 1 a), and there are 

 indications of what may be the eight longitudinal ribs formed of the linear series of 

 thread cells found in the genus Ectopleura. The above species is quite distinct from 

 the only other Ectopleura, E. dumortierii. Van Beneden. 



Locality. Blanche Bay, New Britain. 



' British Hydroid Zoophytes, 1868, p. 111. 



