178 MR. W. WEST 0^ THE FRESHWATER 



This variety was as rough (if not rougher) than forma major, 

 Wille (Ferskv. fr. Nov. Semi. p. 51, tab. 13. fig. 54). Kaben- 

 liorst (Flor. Europ. Alg. iii. p. 220) expresses doubt as to 

 whether the membrane is smooth or not ; Brebisson, in Half's, 

 Brit. Desm. p. 213, is silent on the matter. I always find this 

 species to be very slightly granulate. 



tt39. STArRASTRUM subptgm^um, nov. sp. (PI. XXIII. fig. 8.) 

 S. mediocre, circiter tarn longum quam latum, profunde con- 

 strictum, sinu subrectangulari extremo obtuso ; semicellulre 

 latissime cuneatse, ambitu glabrae, dorso subconvexse, raarginibus 

 lateralibus leviter convexis, angulis submamillatis ; a vertice visse 

 triangulares, lateribus subconvexis, angulis submamillatis; mem- 

 brana delicate punctata. 



Long. 42-45 /x ; lat. 43 // ; lat. isthm. 1G /x. 



I. Lough Aunierin. 



Compare with S. pygmceum, Breb., especially "forma in 

 Eacib. Nonn. Desm. Polon. p. 31, tab. 3. fig. 12. 



40. S. ttjrgescens, Be Not. [S. punctulatum, Breb., var. 

 turgescens {Be Not.\ Rabh. FL Europ. Alg. iii. p. 208.] 



II. Cloonee Lough. 



41. S. lanceolatum, Arch. {Rabh. FL Europ. Alg. vu 

 p. 202.) 



II. Adrigole. 



* 



42. S. itfCONSPicuuM, Nord. {Norges Besm. p. 26, tab. 1- 

 fig. 11.) 



Long, cum proc. 15-17 fi ; long, sine proc. 10-11 \i ; lat. cum 

 proc. 11-12-5 n ; lat. isthm. 5*5-6"5 p. 



I. Ballynahinch ; Eoundstone ; Lakes, Clifden to Eound- 

 stone.— II. Upper and Lower Lakes of Killarney ; Glengarriff ; 

 Adrigole ; Castletown. 



43. S. striolatum, Arch. {Fritch. Infus. ed. 1861, p. 740.) 

 Long. 22-5 p ; lat. 19-21 p ; lat. isthm. 10 //. 



I. Near Leenane; Eoundstone; near YVestport ; Ballyna- 

 hinch. 



(Balfs, Brit. Desm 



) 



