74 TROCEEDINGS OF THE MALACOLOGICAL SOCIETT. 



TtjEBONiLLA IIehmia, n.sp. PI. VIT, Fig. 11. 



T. testa compresso-fuslformi, alba, nitida, anfractibus 9-11, quorum 

 2 apicales omnino heterostrophi, globulares, vitrei, casteris ad 

 suturas impressis, Isevibus, pauUulum ventricosulis, undi(iue longi- 

 tudinaliter laevicostatis, costis arctis, nitidis, numero ultimum apud 

 anfractum circiter 18, interstitiis sub lente delicatissime spiraliter 

 striatis, apertura ovata, labro tenui, fere recto, columella obscure 

 uniplicata. Long. 4'5, lat. 1-25 mm., sp. maj. ; long. 4, lat. 1mm., 

 sp. rain. 



Hitherto confounded with T. terehrina, Melv., which, first discovered 

 bv Mr. Abercrombie at Bombay, has been found to occur in the Gulf 

 of Oman also, this new species, one of the most distinct of the many 

 affecting this region, may be recognized by its compressedly fusiform 

 build and 9-11 whoi'ls, the lower ones mostly soraewliat pinched in 

 towards the centre, causing a slightly sinuous contour. The fine 

 spiral striations may serve to distiiiguisli it at once from the perfectly 

 smooth T. terehrina The columella is very obscurely once plicate, 

 showing a possible transition to, and link with, Pyrgulina. The study 

 of the Twrhonill<B, in these seas, as elsewhere, presents numberless 

 difficulties, especially as regards the hasilicasororia section, which 

 abound in every dredging, and vary to a considerable extent. The 

 form of the heterostrophe apex may serve as an index to specific 

 character, but it is most likely that the q^ ^'^^ 9 present shell- 

 modifications difficult — indeed, with our present state of knowledge 

 almost impossible — to grasp. 



Odostoiiia (Pyrgulina) herviertoides, n.sp. PI. VII, Fig. 12. 



0. {Pi/rgulma) testa angusta, minima, alba, cylindracea, nitida, 

 anfractibus 6^, quorum I^ apicales vitrei, heterostrophi, globulosi, 

 cseteris fere rectis, apud suturas paullum impressis, undique longitudi- 

 naliter costulatis, costulis rectis, crassis, numero ad 16 ultimum apud 

 anfractum, interstitiis Itevibus, apertura ovata, peristomate continuo, 

 extus fere recto, columella uniplicata. Long. 3, lat. 1 mm. 



Minute, white, the straight longitudinal riblets being thick and 

 large, proportionately spc-aking, with the interstices quite smooth. In 

 miniature, much resembling superficially Herviera isidella,^ M. & St., 

 ,from the New Caledonian region, or Elma livida, Sowb.,^ from the 

 Philippine Islands, which is, I consider, synonymous with R. isidella. 

 Indeed, these may all some day be relegated to the same genus. 



Odostomia (Pykgulina) tenerrima, n sp. PL VII, Fig. 13. 

 0. {Pyrgulina) testa minutissiraa, alba, fusiformi, delicata, an- 

 fractibus 4-5, quorum 1-2 apicales planato-globosi, vitrei, caeteris 

 gradatulis, longitudinaliter costatis, costis prominulis, superne angu- 

 latis, interstitiis loevibus, apertura ovata labro fere recto, ad suturam 

 angulato, columella paullum excavata, obscure uniplicata. Long. 1'75, 

 lat. 0*5 mm. 



' .Jduni. of Conch., vol. ix (1899), p. 186, fi.;?. 



• I'roc. Make. See, vol. iv (1901), p. 210, pi. xxii, fig. 8. 



