30 LIEUT.-COL. H. H. GODWIN-AUSTEN ON [Jan. 6, 



Fortunately a few specimens were preserved in spirit by Mr.Everett, 

 and I am thus able to give the following detailed description : — 



Animal, pale ruddy colour with small black specklings. The 

 dorsal lobes are very considerably reduced in size ; they present a 

 very small lappet-like left dorsal and a fringing right dorsal lobe, 

 and no shell- lobes in the spirit-specimen. 



The odontophore consists of numerous teeth in the rows ; the 

 laterals very minute and unicuspid ; the centrals are simple, straight- 

 sided, spear-shaped teeth without cusps : 



50 . 60 . 18 . 1 . 18 . 50or 60 



78 . 1 . 78. 



The jaw is arched with a central projection. 



The generative organs (Plate V. fig. 5) are interesting because they 

 are, as regards the amatory organ, like some other forms from the 

 same region, and present a type not yet known to exist in India. 



The male organ is simple, bent on itself; the amatorial organ 

 has at the free end a large secretory gland, made up of five separate 

 glands ; a short musnular cylindrical part comes next, armed at the 

 lower part with a very beautiful fine calcareous dart 3'25 millim. in 

 length (figs. .5 a and 5 b) ; its position is at the end of a long cylin- 

 drical open sac with rugous sides, near the base of which is the 

 spermatheca. The albumen-gland is large, but the other parts of the 

 generative organs present nothing that differs from the usual form. 



Several of the sinistral shells inhabiting the Malay Archipelago 

 were placed in the genus Ariophanta by Prof. Semper ; but as I 

 have pointed out in 'Land and Freshwater Moll, of India,' p. 133, 

 they are very unlike the type of this genus, which is from Bombay, 

 and require a subgeneric position assigned to them. The principal 

 and remarkable character is the form of the amatorial organ, so 

 well illustrated by Professor Semper on pi. iii. of his fine work on 

 the Land-Mollusca of the Philippine Archipelago, where he figures 

 the generative organs of Ariophanta rareguttata (Adenore), riunphii 

 (Java), nemorensis (Celebes), and striata (Singapore). On pi. vii. 

 of the same work the form of the teeth of the radula of five species 

 is given ; here dissimilarity exists. A. {Amphidroma) martini 

 (Sumatra), rareguttata, and nemorensis have plain simple teeth ; 

 hntm A. rumphii and striata they are tricuspid, merging into bicuspid 

 shape in the laterals. All these species should now be placed in 

 the genus Dyakia. 



DyAKIA INTRADENTATA, n. Sp, 



Shell very similar to D. hugonis in form and coloration, more 

 acute in the spire and rather flatter on the base, with the umbilical 

 region more excavated. The whorls more closely wound. Sculpture 

 coarser and more decussate, that on the lower side finely papillate. 

 Looked at from below there is a very remarkable dent or small 

 depression indicating the presence of an internal tooth, and this is 

 situated at the distance of exactly half a whorl from the aperture. 



Molu Mountains, in Dr. Hungerford's collection (Boxall). 



