90 Journal of the Asiatic Society of Bengal [Febniaiy, 1907. 



species floating on the surface of small artificial reservoirs in Maj 

 at Kurseongin tl»e Eastern Himalayas (alt, 5,000 feet). P. einar- 

 ginata has also been recorded from the Malay Peninsula, Japan, 

 Australia and South America, as well as as from Europe and North 

 America. 



My remarks as to seasonal occurrence and the production of 

 statoblasts in P. repens apply also to this form. 



Plumatella allmaxi, Hancock, 



P, allmani, P. diffusa, P. jugalis, P. dumortei and ( ?) P. elegans, 

 Allman, pp. 105, 106, 107, 108, pi. vi, figs. 1, 2 ; pL viii. P. princeps 

 (part,) and P. polymorpha {part,), Kraepelin, pp. 199, 122. 



It is very difficult to draw up an exact definition of the forms 

 I have grouped under the name P. allmani ; indeed, it is even 

 possihle that they are not specifically distinct from those grouped 

 together as P. emargznata; hut in India, at any rate, the former 

 not only merge into one another, hut have certain characters in 

 common hy which they may be distinguished from the latter. 

 In the first place, the pigmentation of the zooecia, which is more 

 intense in older than in younger colonies, is less intense, if it is 

 present, in what I call P. allmani than in what I call P. emqrgi- 

 nata^ and is more translucent even when it is definitely present ; 

 in the second, the zooecia are irregular in outline and are more or 

 less contracted at their hases, unless the colony is actually under 

 tension ; while, in the third, although the free statoblasts are 

 always elongated as a whole, with rounded ends, the central 

 capsule, which varies greatly in shape, is small as compared with 

 the ring of air cells. Kraepelin considers the proportions of the 

 statoblast a very important character in differentiating F. prin- 

 ceps from P. polymorpha, although this is not a specific feature 

 in P, philippinensis. I find, however, that in certain cases they 

 are by no means constant, and the limits of variation given by 

 Kraepelin himself are considerable. 



The forms referred to by me 



no. 



September attached to the leaves and stems of various water- 

 plants floating on the surface and growing at the edge of the lake 

 Bhim Tal in Kumaon (altitude 4,500 feet). A large number of 

 specimens were obtained, so me being apparently much younger than 

 others, although all the colonies were small, covering less than a 

 square inch in area. It seemed possible at first sight to separate 

 them into two lots, the extreme phase of one of which agreed 

 exactly with HancocVs figure of P, allmani, while that of the other 

 closely approached AUman's P. elegans, A closer examination, 

 however, showed a large number of intermediate stages not only 

 as regards colonies but also as regards individual zooecia. All 

 the colonies agreed in being adherent to their supports so far as 

 the proximal and middle parts of the zooecia were concerned ; but 

 m those which were attached to plants with divided Jeayes, the 

 zooecia often extended across the space between two leaflets. This 



