202 Mr. W. H. Benson on the Characters 



anfractibus 5 convexiusculis, peimltimo ventricosiori ; apertura 

 magna, subcirculari ; peristomate simplici, reflexo, subrevoluto, 

 marginibus callo parietali teiiui junctis ; tubuli suturalis parte 

 externa longa, pone junctionem labri breviter arcuatim elevata, 

 suturam subtus exhibente ; umbilico impervio. 



Long. 71, diam. 5 mill. Long, apert. (peristomate incluso) 4 mill. 



Ilab. prope Darjiling, iu montibus Himalayanis Sikkimensibus. 

 Teste H. Blanford. 



A most interesting new form, intermediate between Dr. Pfeif- 

 fer's genus Rhaphaulus and the Sikkim and Burmese forms of 

 Alycceus exhibited in A. constrictus, Urnula, and Amphora, B. 

 In the last-named shell the sutural tube commences at a very- 

 short distance behind the mouth. In Streptaulus the tube is 

 first internal, and on arriving at the aperture is suddenly re- 

 flected, and instead of forming an opening in the lip above the 

 aperture as in R. bombycinus, or ending in a short upright tube 

 as in R. Lorraini or Chrysalis, Pfr., it describes a short arch be- 

 hind the lip, and then runs to some distance along the external 

 suture, as in Alycceus. In texture and colouring Streptaulus 

 agrees with Rhaphaulus, not with Alycaus, and it is entirely 

 deficient in the strangulation and swelling which characterize 

 the anterior portion of the last whorl in all the species of the 

 latter genus. It inhabits the same tract with Megalomastoma 

 funiculatum. None of the larger Pupiform Cyclostomacea are 

 known to travel farther towards the north-west. 



Diplommatina diplocheilus, Bens., n. s. 



Testa dextrorsa, vix rimata, ovato-conica, subfusiformi, medio ventri- 

 cosiori, solidiuscula, carneo-albida, vix translucente, leviter iiitente; 

 spira conica, apice acnto, sutura profunda ; anfractibus 6^-7 con- 

 vexis, primis costatis, 3 postremis laevioribus, antepenultimo 

 majori tumido ; apertura verticali subauriculari, pallide carnea, 

 nitente, plica coluniellari valida nutante munita ; peristomate du- 

 plici, interno continuo expanso, exterior! planato-expanso, infra 

 sinistre angulo saliente desinente, marglne sinistro sinuate, callo 

 parietali magno, expanso, superne suturam fere attingente, subtus 

 soluto marginem elevatum efformante. Operculo retractili. 



Long. 3, diam. 2 mill. 



Hab. ad Teria Ghat, Montium Khasia dictorum portam, satis fre- 

 quens. Teste W. Theobald. 



This shell, which, although abundant, was local on limestone 

 rocks, belongs to the division of Diplommatiyia with a conspi- 

 cuous plait at the edge of the aperture, described by the Messrs. 

 Adams as Paxillus, from the Bornean type " adversa," which 

 Mr. H. Adams now regards as a Diplommatina. The operculum 

 was remarked by Mr. Theobald when the species was freshly 

 taken. Diplommatina Huttoni, Pfr., and the two following 



