Freshwater Algse of North Wales' By Wm. West. 289 
C. exiguum Arch. C. 
G. Meneghinii Breb. D., B., P., S., Do. 
var. angulosum (Breb.) Eabh. {Cosmarium angulosum 
Breb.). A. 
*var. simplicissimum Wille. A. 
C. striatum Boldt. A. 
This rare species has been previously noticed in Scotland. 
G. Regnesii Keinsch. 0. 
G. crenatum Ealfs. Do., B. 
G. undulatum Corda. B., A. 
G. tetragonum Nag. Bettws-y-coed. 
var. Lundellii Cooke. C. 
G. tetraophthahnum (Ktz.) Breb. P., B., Do. 
The form of this figured by Cooke has fewer granules than that 
given by Ealfs ; the Welsh forms noticed were nearer the figures of 
the latter, but the forms I see more often have generally a few more — 
though rather smaller — granules than the figure of Ealfs, and the 
semicells are somewhat suhpyramidal and shortly subtruncate, hardly 
“ semiorbicular.” 
var. SUBROTUNDUM nov. var. Fig. 25. Newborough 
Warren. 
Yar. sinu apertissimo semicellulis subrotundis facto. 
Long. 137 /i,; lat. 79 /x; isth. 20 /x x 35 />t. 
This differs from the type in the open sinus caused by the sub- 
rotund semicells. 
G. Brehissonii Meneg. B., D., P., Do., Newborough Warren. 
G. conspersum Ealfs. B., D., A. 
G. quadrum Lund. C. 
G. quaternarium Wittr. & Nord. P. 
G. margaritiferum (Turp.) Meneg. B., P., S., A., Llandudno. 
G. Portianum Arch. C., P., A., Do. 
G. reniforme (Ealfs) Arch. C. 
G. Logiense Biss. B., Bettws-y-coed. 
G. punctulatum Breb. C., B., S., P., Twll Du. 
var. rotundatum Klebs. S. 
Long. 35 jx; lat. 28 /x. 
G. Blyttii Wille. C., P. 
G. orthostichum Lund. C. 
G. botrytis Meneg. Common. 
G. qyrdemorsum Breb. Do., A. 
G. biretum Breb. D. 
Long. 75 /x; lat. ad apices 61 /x; lat. isth. 17 '5 /x. 
C. CONTROVERSUM nov. sp. Fig. 31. 
C. medium, granulatum, dimidiam partem circa longius 
