On new Mollushs from South Africa. 237 



XXVII. — Descriptions of Nine neto Terrestrial and Fluviatile 

 Mollushs from South Africa. By James CosMO Melvill, 

 M.A., FiL.S., and John H. Ponsonby, F.Z.S. 



1. Pisidium Langleyanum^ sp. n. 



P. testa trigono-ovali, tumida, ina3quilaterali, postice prodiicta, 

 antice breviter truncata, exilissime concentrico-striata ; urabonibua 

 subpromineutibus obtusis, dentibus minutissimis, normalibus. 



Loug. 2|, lat. 3 mill. 



Hah. Port Elizabeth. 



We have the advantage of the high corroborative authority 

 of Dr. Clessin respecting the claims of this little raollusk to 

 rank as a new form of a most obscure and difficult genus. 

 It is perhaps the smallest of all the species. 



2. Cyclostoma transvaalense^ sp. n. 



C testa conoidea, efFuso-])yramidali, fuscescente, profundo sed 

 anguste umbilicata ; spira data ; anfractibus quinque, convexis, 

 duobus ultimis rapide accrescentibus, ad suturas canaliculatis, 

 costis transversis regulariter sj^iraliter decussatis ; peristomate 

 rotundato, tenui, eontinuo, baud reflcxo. 



Long. 7, lat. 6 mill. 



Hah. Pretoria. 



A beautiful shell, of effuse growth, deeply but somewhat 

 narrovvly umbilicate, the sulcations on the whorls forming a 

 close, parallel, equidistant series of grooved lines, the inter- 

 stices between which are densely superficially and longitu- 

 dinally lineated, channelled at the sutures; lip thin, con- 

 tinuous, not reflected. 



3. Helix [Dorcasia) namaquensis, sp. n. 



H. testa vix umbilicata, globulosa, superficie minutissime longitu- 

 dinaliter rugoso-striata, pariim nitente, f usco-gilva, tenui ; anfrac- 

 tibus quinque, ultimo inflato, rotundato, ad labrum submalleato ; 

 columella la)vi, albida ; apertura ovata ; peristomate reflexo, albido, 

 margine columellari calloso, subdilatato ; umbilicum obtegente. 



Long. 30, lat. 27 mill. 



Hah. Namaqualand {Mr. Lightfoot), 



A distinct addition to the section Dorcasia^ of a form which 

 may very probably exist in collections, in company with the 

 next [H. jjorphyrostoma), mixed up with specimens of H, 

 rosacea and glohulus (Miill.), from which it differs by the 

 characters given above. Two specimens in coll. J. H. P. 



