11 
New British Freshwater Algae. By William West. 
seriebus transversis, dorso subrecto, ventre convexo, utrobique 
polo in processibus brevibus tridentatis producto; a vertice 
visae triangulares lateribus concavis, ad basim processuum 
prominentiis duabus brevibus divergentibus bifurcatis ornatae. 
Long. 22*5 fx; lat. cum proc. 39 p; lat. isthm. 10 fx, 
Hob. New Galloway, Co. Kirkcudbright, Scotland 
(J. M‘ Andrew). 
Compare with 8. arcuatum Nordst. 
S. asperum Breb. f. monstrosa. Fig. 48. 
Long. 36* 5 fx; lat. 34*5 /x; lat. isthm. 13*5 fx. 
Rah. Witherslack, N. Lancashire. 
S. subpygm^um West (Freshw. Alg. of W. Ireland, p. 178, 
pi. xxiii. fig. 8.). 
f. glabra. Fig. 43. 
Forma membrana glabra. 
Long. 42 fx; lat. 39*5 fx; lat. isthm. 22*5 fx. 
Rah. Borrowdale, Lake District. 
The specimens were surrounded by a gelatinous matrix 71 fx in 
diameter. 
S. LANCEOLATUM Arch. 
var. compressum var. n. Fig. 22. 
Yar. cum sinu angustiore et apice late truncato ; a 
vertice visa lateribus concavioribus. 
Long. 17*3 fx; lat. 21*1 /x; lat. isthm. 7*5 fx.. 
Hab. New Forest, Hampshire. 
S. inconspicuum Nordst. var. crasshm Gay (Essai Monogr. 
Conjug., p. 68, t. 3, f. 10). Forma pentagona. 
Long. 15 ’5 fx; lat. 15 fx; lat. isthm. 6 ’5 fx. 
Rab. Glen Caragh, Co. Kerry, Ireland. 
S. pyramidatum West (Freshw. Alg. of W. Ireland, p. 179). 
8. murieatum Breb. var. acutum West. (Freshw. Alg. of 
IN'. Wales, p. 294, tab. 5, fig. 14)]. 
var. coilon var. n. Fig. 46. V 
Yar. spinis numerosioribus ; a vertice visa lateribus con- 
cavis et angulis subacutis. 
Long. c. spin. 80 yn, sine spin. 72 '5 /x; lat. cum spin. 
65 fx, sine spin. 60 [x\ lat. isthm. 17*5 p. 
Rab. Corrie Ceandor, Scotland. 
Perhaps St. spinosissimum Turn. (Freshw. Alg. of E. India 
p. 113, t. xiii. f. 7) should be called var. spinosissimum (T.) of this 
species. 
S. grande Buln. in Hedwigia, 1861, p. 51, t. ixA, f. 14. 
var. parvum var. n. [$. brevispina Breb. var. inerme 
Wolle (Freshw. Alg. of U.S., pi. lxii. figs. 9-10) non Wille 
(Freshw. Alg. fra Nov. Semi., p. 52, t. xiii. f. 62)]. Fig. 51. 
