Yol. 68.] LOWER CARBONIPEEOUS GASTEROPODA. 299 



in identifying a shell from Lowick with the species under discussion ; 

 he states that it possesses 



' an extremely prominent, flat keel, truncated or quadrate at its narrow, outer 

 edge, and having the sinal band along its upper flat side, bounded internally 

 by a faint obtuse ridge.' 



Though both species when entire have a prominent keel and similar 

 test-structure, I am convinced that they are distinct : for in the 

 Lowick shell this keel is more prominent, and there is a strong 

 thread at a little distance above which is not present in the Irish 

 specimens ; the former is also smaller, the sutures are deeper, and 

 the convexity of the whorls is greater. 



One example of Tr. griffithi shows traces o£ several fine spiral 

 threads on the base, and another has a single strong thread on the 

 body-whorl a short distance below the band. 



Dimensions.— The holotype (PL XXVII, fig. 2) is in the 

 Griffith Collection, i^ational Museum of Ireland, Dublin ; it con- 

 sists of five whorls the length of which =7*6 centimetres, and its 

 greatest width =10'9 cm. Another example in the General Col- 

 lection of the same Museum (PI. XXVII, figs. 1 a-1 c) has three 

 whorls preserved, which =10'3 cm. in length and 12*6 cm. in 

 greatest width. The specimen (PI. XXVII, tig. 3), presented by 

 Sir Richard Griffith to the Sedgwick Museum, consists of the half 

 of a single whorl which measures 8 centimetres in width. 



Localities. — The holotype is from Millicent, Clane (Kildare); 

 two shells associated with it, as well as"an individual in the Sedgwick 

 Museum, are from Ardclogh, Eathcool (Dublin). Three specimens 

 in the General Collection of the Xational Museum of Ireland, 

 Dublin, are simply labelled ' from Kildare ' and another in the 

 British Museum (Natural History) has no more definite locality 

 ascribed to it than Dublin. 



Horizon. — Lower Carboniferous Limestone. 



it 



Tropidostropha punctata, sp. nov. (PI. XXVIII, figs. 1-2 c.) 



Fleurotomaria griffitUi (pars) F. M'Coy, 1855, ' Brit. Pal. Foss.' pp. 528-29 

 (non PI. griffitUi M'Coy, 1844, ' Syn. Char. Carb. Limest. Foss. Irel.' p. 40). 



Diagnosis. — Shell large. Whorls about six, with a sharp 

 flange-like keel a little above the middle of the body- whorl, and on 

 the penultimate whorl about a third of its height from the suture ; 

 very convex, except above and below the keel, where they are 

 concave. A strong thread a short distance above, and a very fine 

 one immediately below, the keel. Lines of growth strong, irregular, 

 varying in thickness, and sometimes interrupted or bifurcating. 

 Whole surface of the test covered by numerous very fine spiral 

 lines. Umbilicus wide, partly covered by a reflection of the inner 

 lip, which has strongly impressed lines running down it. 



Remarks and resemblances. — It has already been stated 

 that M'Coy erroneously considered a specimen of this species in 

 the Sedgwick Museum from Lowick conspecific with Tr. griffithi, 

 and the distinctive features were pointed out. The space between 



