150 COLLECTIONS FEOM MELANESIA. 



the body. Polian vesicle ? Length 85, 62 miUiin. ; greatest breadth 

 17*5, 17"5 millim. 



Port Jackson. 



Save in the complete absence of spicules this species would not 

 appear to have any resemblance to the T. imrmis of Heller, the 

 shorter body of which, attenuated at both ends, is said to have a 

 very thin integument and to be of a yeUowish-grey colour. 



11. Thyonidium schmeltzii. 



Ludwig, Semper's Arbeiten, ii. p. 94. 



As there is only one specimen of this species, I have been obliged 

 to content myself with an examination of the integuments, where 

 the " morgenstemahnliche Gebilde " were found in abundance in 

 the outer layer. 



Warrior Keef, Torres Straits. 



12. Orcnla cuctuniformis. 

 Semper, Sol. p. 244. 



Port Molle. 



13. Phyllophorus proteus. (Plate IX. figs. F, F'.) 



Body varying greatly in form, being saccular, swollen, or elon- 

 gated ; in the last case it is narrower behind than in front, and 

 pretty regularly convex above. The integument, which is rather 

 thick, may be black, and the colour rendered more marked by the 

 lightness of the suckers, as there may be merely dark longitudinal 

 bands, or the whole body may be greyish, and the only black spots 

 the tips of the suckers. The suckers themselves always have a 

 wrinkled appearance, but no definite statement can be made as to 

 their arrangement on the body. 



The retractors are triangular in form and considerably enlarged 

 at their origin ; the buccal ring is well developed, the radial pieces 

 being very large, and the interradial dagger-shaped ; both are rather 

 deeply excavated above (fig. F'). The spicules in the suckers present 

 an appearance not unlike that seen in the zoogloea-stage of Bao 

 ieriwm termo ; the spicules of the integument are more or less four- 

 sided, four-chambered bodies, made np of somewhat delicate bars, 

 forming a treUis-work. ' 



Port Molle ; Clairmont and Thursday Islands ; Alert Island (7 fms., 

 sand). 



14. Stereoderma validum. (Plate IX. figs. E, a-f.) 



Body elongated, tapering more at its posterior than at its anterior 

 end ; the ventral surface a little conves, the dorsal concave. A 



