liverpool fresh water alcle. 283 



Multinucleate . 

 Family. — Vaucheriacee . 

 Vaucheria sessilis, Vauch. 



Moreton, C. (B), Walton, L. (D), Kensington, L. (N), 



Bromborough, C. (N). 

 V. sessilis, var. cwspitosa, Vauch. 



Formby, L. (N), Barton, L. (N), Kensington, L. (N). 

 V. sessilis var. repens, Vauch. 



Formby, L. (N). 

 V. dicliotoma, Lyngb. 



Aintree, L. (D, N). 

 V. terrestris, Lyngb. 



Kensington, L. (N), Huyton, L. (N). 

 V. geminata, D. C. 



Moreton, C. (B). 

 These species very freely distributed in ditches, damp 

 stones, clayey soil and similar places, also found floating 

 in mass on ponds. They are subject to attacks from 

 parasitic Botiferons of the genus Notommata (vide paper 

 by W. Narramore, read before the Liverpool Microscopical 

 Society, November, 1889). 



V. sessilis is subject to much variation in the reproduc- 

 tive structures, one of the most striking examples is from 

 a specimen gathered at Formby in March, 1891, an 

 oogonium and antheridium of the specific type developed 

 directly from the zoospore, whilst from the tubular portion 

 of the same specimen are antheridia and oogonia of the 

 types represented by V. terrestris, V. dicliotoma and V. 

 hamata (PL XVI., fig. 2, 3). This alga was taken from 

 a ditch on sandy soil, the conditions being subject to many 

 in the course of a season. 



CCENOBIEE. 



Family. — Volvocinee. 

 Volvox globator, Linn. 



