7i 



Bowerbankia densa Farre, 1837, t. cit., p. 391, Pis XX, XXI. 



Bowerbankia imbricata (incl. B. densa) Hincks, 1880, t. cit., p. 519, PI. LXXIII, figs 1, 2. 

 ? Bozverbankia imbricata, form densa Hincks, 1884, "Pol. Q. Charlotte Is", Ann. Mag. Nat. 

 Hist. (5) XIII, p. 207. 



'? Stat. 50. Bav of Badjo, W. coast of Flores, o — 40 Metres; mud, sand and shclls. 

 325- J- ' 

 382. B. Stat. 64. Kambaragi Bay, Tanah Djampeah, O — 32 Metres; coral, coral-sand. 



338. B. Stat. 71. Makassar, o — 32 Metres; mud, sand with mud, coral. 



' ' > Stat. 164. i°42.s S., I30°47'.5 E., 32 Metres; sand, small stones and shells. 



374. K. (No locality recorded). On Peropliora. 



Japan, Mus. Zool., Cambridge, Reg. June 23, 1902 (A. OwsTON Coll., 27. D., off Tokyo, 

 150 fathoms). (On Bugula johnstoniaè). 



Characters of the material here recorded: — 



Zooecia arising in small groups from a creeping stolon ; sometimes less definitely grouped 

 or even arising singly. The stolon is occasionally septate, and gives off a few branches here 

 and there. Zooecia elongate, subcylindrical, straight or somewhat curved, usually paired, their 

 basal ends much wider than the stolon, sometimes produced into processes, and projecting on 

 either side of it. Orifice square. Vestibule rather long, but variable in length ; containing a 

 moderately developed collar. Tentacles not numerous, probably not more than 10. Pharynx 

 large, oesophagus short, bent during retraction, passing into a short conical proventriculus, 

 which is succeeded by a well marked gizzard. Stomach and caecum large; intestine and rectum 

 narrow. Parietal muscles extending along the whole length of the zooecium, the fibres usually 

 arranged singly. 



I think I am right in referring all the specimens above recorded to a single species; 

 though some of them are obscured by the remains of Sponges in which they were more or 

 less embedded. As in many other species of Ctenostomata, the zooecia vary much in length ; 

 but, as in other cases, this appears to depend largely on changes accompanying the histolysis 

 of the polypide. The best specimen, part of which is shown in figs 15, 16, is 374. K., the 

 locality of which, by some oversight, was not recorded. It is growing on the oral end of a 

 Perophora, to which the stolon is for the most part adnate. The complete zooecium shown in 

 fig. 16 is 980 y. long and 190 u. in diameter. The longest zooecium in fig. 15 is 1200 u. in 

 length ; but its vestibule has lost its connexion with the rest of the polypide, preparatory to 

 histolysis, and the collar is completely protruded. The cuticle is very thin and transparent. The 

 vestibule is provided with four groups of parieto-vaginal muscles, close to its proximal end ; and 

 there are four groups of similar muscles, close to the first set, but inserted into the junction 

 of the vestibule and tentacle-sheath. 



Several of the specimens show occasional diaphragms, traversing the stolon; but I am 

 not able to state the typical arrangement of these structures. 



The specimen from Japan appears to belong to the same species; but the preparation 

 is not a very successful one. Hincks l ) has alluded to "a Vesicularian, apparently allied to 



1) Hincks, T., 1880, t. cit., p. 519, note. 



71 



