148 MK. W. WEST OX THE FBESHWATEE 



signite tricrenatis ; membrana distincte callosa ad apicem incisu- 

 arum parvarum et ad medium ; a latere visae late ovatae. 



Long. 36-38 ll ; lat. ad bas. semicell. 23-25 li ; lat. ad apic. 17 

 -18 /i; lat. isthm. 7'5-8'5li; crass. 16 li. 



I. Ballynahinch ;* Athry Lough. 



The Cosmarium venustum, Arch, in Wolle's Desm. TJ. S. (p. 68, 

 pi. 16. fig. 37), may be referred to a less crenate form of this 

 variety. The thickening on the inside at tbe base of the notches 

 makes this variety appear at first sight more deeply crenate than 

 it really is. 



tfVar. hypohexagoxum, nov. var., f. i^crassata. (PL 

 XXIV. fig. 23.) 

 Forma subtricrenata, membrana forte incrassata inter undulas. 

 Long. 25 li ; lat. 20 ll ; lat. isthm. 5 fx ; crass. 11 li. 



I. Athry Lough. 



tt36 



(PI. XXI. fig. 2.) 



G. minutum, paulo longius quam latum, prof undissime con- 

 strictum, sinu lineari angusto, extremo ampliato ; semicellulse 

 subhexagonae, marginibus lateralibus superioribus triundulatae 



s includente), apice late truncatae et subconcavae ; a 



vertice 



• 



adratae 



atis ; membrana laevis ; pyrenoidibus singulis. 



Long. 11 Li ; lat. 9'5fi ; crass. 5 ll. 



I. Ballynahinch. 



Compare with C. Ifeneghinii, Breb.,var. naniwi, Wille (Ferskv. 

 Alg. f. Nov. Semi. p. 43, tab. 13. fig. 37). 



37. C. Meneghinit, Breb. in Balfs, Brit. Desm. p. 96, tab. 15. 

 fig. 6. 



I. Moher Lough ; near Recess ; Lough Aunieriu ; Derryclare 

 and Nabincka Loughs ; Lough Shindilla ; Lakes east of Lough 

 Bofin. — II. Lough Guitane ; Cromagloun ; Upper and Lower 

 Lakes of Killarney ; Carrantuohill ; Kenmare; GlengarrifF; Glen 

 Caragh; Cloouee Lough; Mallow; 8 m. S. of Kenmare. 



Forma octangularis, Wille. (Ferskv. Alg.fr an Nov. Semi. 

 p. 43, tab. 12. fig. 35.) 

 I. Creggan Lough; Ballynahinch; near Westport ; Lakes E. 



of Lough Bofin.— II. Upper and Lower Lakes of Killarney ; 

 Cloonee Lough ; Mallow. 



