1 70 N. Annandale : Three Indian Phylactolxmata. [VOL. II, 



the zoaria dead and decomposed, in some only fixed statoblasts 

 remaining. 



I am by no means sure that this form is more than a local 

 race of Mr. C. Rousselet's P. tanganyikce , of which, by the kind- 

 ness of Mr. R. Kirkpatrick, I have been able to examine one of 

 the types. I have, however, submitted a specimen of the Bombay 

 form to Mr. Rousselet, who considers it quite distinct, suggesting 

 that it maybe related to Allman's P. fruticosa, on account of a 

 similarity in the measurements of the statoblasts he himself has 

 examined. But what I call P. fruticosa is a slender species with 

 more or less free colonies., a faintly tinted cuticle, and a rounded 

 distal extremity to the zooecia ; and in my diagnosis of this form I 

 follow Allman's figures {Mon. Freshwater Polyzoa, pi. vi). My new 

 species possesses none of these characters and differs from P. tan- 

 ganyikce only in the following points: (i) its darker colour; (2) its 

 strong keel, which gives its basal half almost a triangular outline in 

 cross-section; and (3) its possession of free statoblasts. It resembles 

 the African species in characters perhaps more important, viz., in 

 its annulate and truncated zooecia and its habit of partially embed- 

 ding its colonies in the substance to which it adheres. 



The truncate appearance of the zocecia is naturally most dis- 

 tinct when the polypides are contracted. In this condition the 

 zocecia apparently resemble those of P. philippinensis , Kraepelin, 

 between which and the African form P. bombayensis is evidently in 

 some respects intermediate. When the polypides are expanded it 

 is seen that there is a much sharper division between the zocecium 

 proper and what Allman calls the tentacular sheath than there is 

 in most species of the genus, in which, as a rule, the chitinized 

 cuticle fades away gradually at the distal extremity of thezooecium, 

 giving place to a soft membrane. In P. bombayensis and P. tan- 

 ganyikcB, however, and apparently in P. philippinensis also, the 

 walls of the zooecmm are unusually stout and terminate abruptly, 

 the tentacular sheath and the parts immediately adjacent to them 

 being extremely delicate and collapsing completely when the 

 polypide is drawn into the aperture.' In P. emarginata, which re- 

 sembles these forms to some extent in the thickness of the walls 

 of the zooecia, although the zooecia themselves have a much smaller 

 diameter, the aperture is as a rule more or less lateral, not terminal, 

 and is approached by a distinct triangular patch of rather stout 

 but almost transparent membrane situated on the upper surface 

 of the zooecium, the tip of which is rounded even when the polypide 

 is fully contracted. 



As I find that the statoblasts of the Indian forms of Plumatella 

 do not afford, in their exact actual or proportional measurements, 

 any safe specific criterion, I have purposely omitted to give measure- 

 ments of those of P. bombayensis ; but I may say that, in the few 

 specimens I have examined, the breadth equals about two-thirds 



I Probably P. aplinii, MacGillivray, from Australia {Trans. Roy. Soc. Victoria, 

 V, p. 203, i860) also belongs to this group, but the description is very incomplete. 



