103 



gemmule, more numei-ous birotulates, longer or shorter shafts 

 of birotulates etc. There are several forms marked "variety" 

 but none has been found belonging strictly to the named 

 varieties. The species grows on all sorts of supports but is 

 found more frequently on aquatic plants in deep clear water 

 than other forms. 



2. M. Millsii, Potts, Monograph, p. 225. 



Manj" small pieces collected by Mr. Mills in Sherwood Pond, 

 DeLand, Fla. March, 1S84. These fragments are same as 

 those described, hence may be considered "type". It is an 

 elegant species. 



3. M. Everetti, Mills. Monog7'aph, p 230. 



Specimens, compacted masses, the long ropes or fibres of 

 sponge found on plants. Collected by Francis Wolle, Gilder 

 Pond, Mount Everett, September 1882. It is an extremely 

 interesting species owing to the fact that it has birotulate 

 dermal spicules. 



\. M. Leidyi, Carter. Monog7'aph, p. 212. 



Several good specimens. .Schuylkill River, Philadelphia. 



5 M. plumosa, Carter, variety Pabneri, Potts. Moiiogj-aph p. 234. 



Two examples evidently from the describer of the species 

 and hence of the type. Locality, Colorado river, Lerdo, 

 Sonora, Mexico. This sponge was found on rocks and over- 

 hanging trees at a level that rendered it impossible that it 

 should have been submerged more than a few months in the 

 year. 



f). M. crateriformis, Potts. Mfljiograp/i, p. 22S. 



One specimen on bark, Niagara River. It was marked 

 "variety," but on comparison I find no difference between it 

 and that found at Columbiis, O., which agrees well with 

 the original description. I think the specimen is normal. 



Plciomeyenia was described by Mr. Mills in the P7-oc. Am. 

 Soc. of Mic. VI — p. 147 as a new genus ; the destinctive 

 character was the arrangement of the birotulates in two or 

 more series about the statoblast. . Three species were descri- 

 bed viz: Cahcmetictcs, li'a/A'crz and spinifera. The first two 

 are in the Collection, both type specimens; the former from 

 Calumet River, 111., the second from Ischua Creek, Erie Co., 

 N. Y. Other specialists have not admitted the validity of the 

 genus and the species have been made sjmonyms of. 



t). M. Mulleri, Lieberkuhn. Monograph 224. 



Specimens as above. 



