Mr. W. H. Benson on a new species o/Diplommatina. 331 



aperture in Diplommutina, it is drawn to a greater distance than 

 in any other known upcrculated land mollusk. This habit also 

 accounts for the absence of loose opercula in the boxes in which 

 specimens have been kept, as observed by Capt. Ilutton and 

 myself; the valve is drawn tightly into the narrower whorls, and 

 there remains a fixture, as long as the lower whorls are preserved 

 entire. 



It is worthy of note that, in September 1849, Professor Albert 

 Mousson of Ziirich wrote as follows, when acknowledging speci- 

 mens which I had sent to him : — " En examinant bien atten- 

 tivement I'ouverture de votre Diplommatina folliculus, garnie 

 d'un bord entier, et la costulation exterieure, on est frappe de la 

 ressemblance avec le genre Pomatias, Stud. Veuillez bien en 

 parcourir un plus grand nombre et vous assurer s'il ne s'en 

 trouve pas quelques individus munis encore de leur opercule en 

 parchemin." His prognostication has proved tolerably correct. 



It is desirable that some collector possessing the doubtful 

 Philippine shell, Cyclostoma minus, Sow. (D. Soiverbyi, Pfr.), 

 should devote a specimen to a search for the operculum, which, 

 if the species really belongs to Diplommatina, will doubtless be 

 found in its ordinary retracted position, when its structure will 

 decide the question. 



Diplommatina Australia, nobis. 



Testa sinistrorsa, rimata, subovato-conica, glabra, subremote-costata, 

 pallida cornea, spira ovato-conica, apice acutiusculo ; anfractibus 

 sex couvexis, ultimo angustiore, antice ascendente ; apertura ver- 

 ticali, subcirculari, peristomate dupUce, posteriori expauso, ante- 

 riori expansiusculo, marginibus nitidis, diaphanis, callo jmictis, 

 exteriori superne breviter producto, coliimellari dilatato, tuberculo 

 inconspicuo vel obsoleto. Operculo remoto, normali, lamella vix 

 elevata. 



Long. 3^, diam. vix 2 mill. 



Hab. ad Mount Warren, Point Danger, AustraUae Orientalis. Teste 

 Strange. 



About the same size as D. folliculus, Pfr., it is less acuminate, 

 and may at once be known by its sinistrorse volutions, more 

 distant costulation, and by the produced portion of the outer lip 

 near its junction with the body whorl. The operculum occurs 

 at the distance of two whorls from the apertui-e. Mr. Strange 

 told me that he had found it under dead leaves in the brushes. 

 The occurrence of the genus at such a distant point, in a south- 

 ern latitude, from its Himalayan head-quarters, is an interesting 

 fact. Perhaps diligent search on decayed leaves, in damp situa- 

 tions, may reveal other species in the intervening lands. 



Nice Maritime, 22nd Mai-ch 1855. 



