Mr. H. J. Carter on a Freshtoater Species of Ccratmrn. 229 



XX^^II. — Note on a Freshwatet' TSpecies of Ceratium from the 

 Liike of Nipiee [Naini) Tal in Kumaon. By H. J. 

 Carter, F.K.S. &c. 



Several species of horned Peridinea (viz. of Ceratium) from 

 the Baltic Sea have been described by Ehrenberg and others, 

 while those called by the former C. tripos and C.furca have 

 been seen by MM. Pringshcim and Werncck, respectively, in 

 fresh water also (Clap, et Lachm. ' Etudes sur les Infusoires ' 

 &c. vol. i. pp. 399 and 400). Perty (Zm* Kenntniss &c. 

 p. 161, pi. 7. fig. 13) describes one, under the name of C lon- 

 (/icor7ie, from the Swiss lakes, where they are found; and, lastly, 

 we have them from the lakes of the Himalaya and Lower 

 Bengal, 



Thus my friend Dr. Forbes Watson, of the India Museum, 

 has submitted to me for re- 

 port a glass slide containing 

 several mounted in gum 

 from the lake of Njnee Tal. 



Of these, Mr.' Stewart 

 Clark, Inspector-General of 

 Prisons, N.W.P., who for- 



wards them, states that they 

 are " perfectly visible to the 

 naked eye, chiefly on the 

 surface, 10-15 feet dow^n, 

 very few below 20 feet, and 

 probably none at the very 

 bottom of the lake, which is 

 95 feet deep. 



" They are found in all 

 the lakes of Kumaon at an 

 elevation of from 4000 to 

 6500 feet above the level of 

 the sea. 



"The ordinary beautiful blue colour of the lake at Nynee 

 Tal was at their captm'e, and had been for some months 

 previously, changed to a rusty brown, by the presence of 

 myriads of this kind of Infusorium." 



'J' he chief interest in the species is that, although it is closely 

 allied to C.furca, Elir., yet it must be regarded as a variety 

 of this form, inasnnich as the posterior horn in the figures of 

 the latter given by Ehrenberg (' Tnfusionsthier.') and (^la- 

 j)arede (' Etudes '), respectively, is represented as smooth, while 

 in those forwarded from the lake of Nynee Tal (see figure) all 

 three of the horns are ei|ually though minutely serrated by 



Ceratium kumaonense, dorsal ^■ie^v, 

 maguitied. (Scale l-24tli to l-CiOOOth 

 of an inch.) a, portion of horn inori> 

 mairniliod, to show the disposition of 

 the tubercles; b, point from ■which the 

 fourth horn might be developed ('?). 



