130 A1E. W. WEST ON THE EiiESHWATEK 



fVar. alpinum, Racib. [P. minut. e. alpinum, Racib. (Nonnul. 

 Desm. Polon. p. 5).] 



Long. 125-170 \x ; lat. prope bas. semicell. 12-5-14 \x ; lat. 

 prope apic. 8-10 /u. 



I. Oorid Lough. — II. Cromagloun. 



fYar. polonicum, nob. [P. (Docidium ?) polonieum, Racib. 

 {I. c. f. 12).] 



Long. 145-165 ju ; lat. prope bas. semicell. 12'5-lS /u ; lat. 

 isthm. 10-11 /x ; lat. prope apic. 5-6 p. 



II. Cromagloun. 



The Irish forms of the last four varieties are all of somewhat 

 larger dimensions than the originals. After examining a very 



large number of examples from near Cromagloun, I do not 

 consider that P. polonicum, Sacib., is a distinct species, as forms 

 were noticed connecting it with var. alpinum, Racib. 



ttYar. ceassum, nov. var. (PI. XX. fig. 1.) 

 Var. diametro 4|plo longius, apices versus attenuata, lateribus 



subrectis, constrictione distincta sed levi. 



Long. 71-85 /x ; lat. prope bas. semicell. 16-18 /x ; lat. isthm. 

 13-14 /i; lat. prope apic. 125 p. 



I. Ballynahinch ; Nacoogarrow Lough. — II. Adrigole ; Car- 

 rant uohill. 



ttVar. ceassum, nov. var., f. punctata. (PI. XX. fig. 2.) 

 Membrana distincte punctata. 



Long. 77 fj ; lat. prope bas. semicell. 18 \x ; lat. ad apic. 13 /x. 

 I. Ballynahinch. 



ttYar. ceassum, nov. var., f. inflata. (PI. XX. fig. 3.) 

 P. diametro 3|-4plo longius ; semicellulis distincte inflatis. 

 Long. 65-80 /x; lat. prope bas. semicell. 20-21 /* ; lat. prope 



apic. 135-15 jj. 



This totally differs from var. tumidum, Wille, in its relatively 



greater thickness. 



I. Ballynahinch. 



ttYar. undulatum, nov. var. (PI. XX. fig. 4.) 

 Yar. semicellulis regulariter sed leve 5-undulatis utrobique. 

 Long. 101 /x ; lat. prope bas. semicell. 12*5 H ; lat. prope apic 

 9/x. 



II. Cromagloun. 



