Vol. 68.] KEW LOWEK CAKBONIFEKOFS GASTEEOPODA. 295 



15. Some New Lowee Caeboniferous Gasteeopoda. By Jane 

 LoKasTAFF {nee Donald), F.L.S. (Communicated by Dr. G. B. 

 LoNGSTAFF, M.A., F.G.S. Eead March 13th, 1912.) 



[Plates XXVII-XXX.] 



Eight species are here described, all characterized by the presence of 

 a, band on the whorls : in seven it is probably the result of a sinus 

 or slit in the outer lip, but in the eighth it is merely ornamental, 

 as the lines of growth pass over it. These species are referable to 

 six genera or subgenera, five of which are new, namely Tropido- 

 ■stropha, Treclimannia, Foordella, Tmetonema, and MicroptycJiis ; the 

 •other geuus, Pithodea De Kon., has not been previously recorded 

 from the British Isles. 



Family ? Raphistomidae Ulrich. 

 Teopidosteopha, gen. nov. 



Diagnosis. — Shell conical, of medium height. Whorls with 

 a prominent, flange-like keel a little above the middle of the body- 

 whorl, and considerably below the middle of the penultimate whorl ; 

 convex, except immediately above and below the keel, where they 

 are concave. Test thin, composed of two layers. Outline of the 

 keel slightly convex below, and slightly concave above. Under 

 the keel is an inner, flat or somewhat concave band, covered with 

 arched striae, and formed of the inner shell-layer. Lines of growth 

 strong and irregular : above they slope backwards with moderate 

 obliquity to the edge of the keel, over which they pass without 

 break ; while below they at first curve sharply forwards, and then 

 run almost vertically into the umbilicus. Aperture subquadrate. 

 Umbilicus open. 



Genotype. — Pleurotomaria grifflihi M'Coy. 



Remarks and resemblances. — This genus is suggested for 

 two species, the characteristics of which do not exactly agree with 

 any genus or subgenus known to me. These are Pleurotomaria 

 griffithi M'Coy and Tropidostropha punctata, sp. nov. Both are 

 remarkable for the structure of the spiral band. Owing to imperfect 

 preservation, this is rarely well shown : the outer flange-like keel 

 being often so worn and broken, that merely a blunt or rectangular 

 ridge is left. Three specimens of Tr. griffithi, however, exhibit 

 portions of the flange resting on an inner blunt keel, and one of 

 these in the National Museum of Ireland, Dublin, is sufficiently 

 well preserved to show the structure fairly well. Near the aperture 

 part of the sharp flange is intact, and it is seen to rest upon a 

 band which is almost flat, limited on each side by a thread, and 

 covered with closely packed crescents ; this rectangular band alone 

 remains on the earlier whorls. All the specimens of Tr. punctata 



Q. J. G. S. No. 271. z 



