VOLVOCINE.E. 67 



The author cited then goes on to explain how he conceives the other 

 stages of the Eiidorina are passed, which he had not the opportunity 

 of observing. The whole memoir is one of great interest, and will 

 well repay perusal by those who are investigating this subject. 



Eudorina elegans. EJirb. Monats. Berl., 1831, p. 78. 



Coenobia oval, cells usually 32, globose, either scattered or 

 quaternate, eight at each pole, distributed in three parallel 

 circles, at equal distances from each other, around the periphery 

 of the ccenobium. 



SIZE. Ccenobium -04--15 mm. long. Cells -018--022 mm. 

 diam. 



Rabh. Alg. Eur. iii. 99. Ehrb. Infus. 63, t. iii. Pritchard 

 Infos, p. 520. Carter, in Ann. Nat. Hist., Oct., 1858. 



Pandorina elegans, Dujard. Zoophy., p. 317. 



In standing water. 



Formerly found at Hackney and Hampstead, most abundant in the 

 spring of the year, but doubtless quite extinct at both places. " Clusters 

 are of ten seen," says Pritchard, " in such amazing numbers along with 

 Volvox and Chlamydomonas pulvisculus as to render the water of a 

 decided green colour, especially towards the edges." 



Plate XXVI. fig. 1. a, 16-celled family; 2, sixteen-celled family 

 dividing into a 32-celled family ; 3, part of a family, showing division in 

 pairs ; 4, 32-celled family divided into daughter-families; 5, one-celled 

 daughter-family. All after Stein. 6, colony \\ith three spermatic 

 cells, having burst j 7, spermatic cells X 400 ; 8, spermatic cell X 800 ; 

 9, spermatozoids X 800. After Carter. 



GENUS 41. PANDORINA. Ehrb. (1830.) 



Ccenobium globose or subglobose, invested by a broad colour- 

 less hyaline tegument ; cells green, granulose, globose (16, 32, 

 or 64), included within a single rather thick membrane, bearing 

 two vibrating cilia, with or without a red spot, aggregated in a 

 botryoid manner. 



Propagation the same as in Eudorina. 



Henfrey's emended character of this genus was in the following 

 terms : " Frond a microscopic, ellipsoidal, gelatinous mass, containing, 

 embedded near the periphery, sixteen or more biciliated, permanently 

 active gonidia, arranged in several circles perpendicular to the long axis 

 of the frond. The gonidia almost globose, with a short beak-like 

 process, a red spot, and a pair of cilia which project through the 

 substance of the frond to form locomotive organs upon its surface. 

 Reproduction I., by the conversion of each gonidium into a new frond 

 within the parent mass ; II., by the conversion of the gonidia into 

 encysted resting spores, which are set free and (?) subsequently ger- 

 minate to produce new fronds." Quart. Micro. Journ. (1856), p. 49. 



