The Microscope. 53 



The two kinds of birotulate spiciila found in the statoblast of 

 this sponge, as already described, bring it into the genus Hetero- 

 meyenia Potts. But for this feature it must be classed, at least, as 

 a remarkable form of Meyenia plimiosa Carter. Forty years ago, 

 Mr. Cai'ter, of England, found his specimen of the last named 

 sponge, in the water tanks of Bombay, India. This he described in 

 1849. No other specimen, nor variety of it was found again, till 

 three or four years ago, when Dr. Palmer found a variety of it 

 on the banks of the Colorado river. This was described by Mr. 

 Potts, who named it Meyenia plumosa variety Palmeri. See his 

 description in his monograph of the freshwater sponges. 



As the term used to designate the generic character of this 

 entirely new form is technically expressive of one of its peculiarities, 

 I have thought it best to use a specific term, which is also expressive 

 of the stelliform spicula, which, among all the freshwater sponges, as 

 far as I know, are only found in this and the two allies above named. 

 It will therefore be known as Heteromeynia radiospiciilata. 



This sponge was found in the Ohio river, 12 miles from Cincin- 

 nati, by my friend, Mr. George B. Twitchell, in September, 1887, 

 and sent to me in November, same year. I acknowledge my indebt- 

 edness to Mr. Twitchell for several other specimens found also in 

 the Ohio river. Among them are Carterius tubisperma Mills. A 

 fine specimen of Tubella Pennsylvania Potts, and Spongilla lacas- 

 ti'is Aucht. 



162 Faego Avenue, Buffalo, N. Y. 



ACTINURUS NEPTUNIUS. 



C. C. MELLOR. 



^T"^HIS singular Rotiferm I had the good fortune to find lately on 

 -*- some ceratophyllum, growing in a little pond alongside of a 

 cow stable in one of the suburbs of our city. It was quite a cold 

 morning, about November 1st, when I visited the pond; it was cov- 

 ered with a thin sheeting of ice, and no plants were visible ; but I 

 soon raked some dilapidated looking specimens from the shallow 

 bottom. On examination I found the leaflets swarming with various 

 rotif era and infusoria, but my attention was soon attracted to a rotifer 

 extending itself to a seeming interminable length, and on four slides 

 I discovered fully twenty of them. Further examination proved them 

 to be Actinurus Neptunius, as described in Hudson & Gosse's recent 

 monograph on the Rotifera, and their description coincides exactly 



