184 SOME NEW OH LESS KNOWN DESMIDS FOUND IN N. S. WALKS, 



from Europe. That species, however, is larger, the granules are 

 not confined to the upper angles, nor are the angles ever biden- 

 ticulate at the ends. Moreover the var. triquetrum has " sides 

 deepl}^ sinuous " in end view (Cooke, Br. Desm. p. 109). 



aS'^. varians Rac, Desm. Polon. T.12, f.l; St. Kjelhnanni Wille, 

 Cooke, I.e., T.54, f.9; and St. pygmaeiun Breb., in Boldt. Desm. 

 fr. Gronl. T.2, f.42, are nearest in form to this species, but its 

 end view alone sufficiently marks it off from them all except the 

 last, which is much smaller. 



St. tiara, n.sp. (T.iv. f.l6). 



St. mediocre, ellipticum, paullo longius quam latum, medio 

 sinu aperto cuneato constrictum, isthmo lato. Semicellulae sub- 

 cuneatae, tiaraformes, dorso altissime convexae et verrucosae, 

 apices versus fere acuminatae; angulis lateralibus acuto-rotun- 

 datis granulis in seriebus 3-4 transversalibus ornatis. Semi- 

 cellulae a vertice quadratae; lateribus aequalibus, levissime 

 concavis, angulis acutis. 



Long. 60; lat. 54/z. 



Ewenmar Station, near Trangie. 



Compare St. Pringlei Wolle, T.50, f.25, and St. validum West, 

 Desm. N. Amer. 1896, T.16,f.36. 



St. cruciforme, n.sp. (T.iv. f.l7). 



St. magnum, oblongum, tam longura quam latum, medio sinu 

 brevi acutangulo constrictum, isthmo angustissimo. Semicellulae 

 subcuneatae, lateribus supra basin paullo inflatis, dorso truncatae 

 verrucis truncatis emarginatis 4 instructae; angulis superioribus 

 in processus binos, unum horizontaliter, alterum radiatim, pro- 

 ductis; processibus 5-denticulatis 3-4-fidis. Semicellulae apud 

 angulum sub processu inferiore granulis singulis et verrucis 

 emarginatis singulis instructae; a vertice triangulares, lateribus 

 rectis intra quemque marginem serie verrucis lunatis 4 et granulis 

 binis apud angulos ornatae; angulis in processus binos protractis. 



Long.c proc. 90; long.s.proc. 60; lat. c.proc. 90-102; lat.s.proc. 

 54/i. 



