1893.] SPECIES OF THE LAITD-MOLLUSCAN GENUS ALTC^TJS. 595 



on the swollen part o£ the last whorl, on the apical whorls it is 

 close and fine ; colour ochre ; spire somewhat flattened, apex 

 blunt ; suture deep ; whorls 4, the last moderately swollen ; sharp 

 constriction in front of sutural tube, followed by a strong ridge 

 which is contiguous to the crenulate peristome ; aperture circular, 

 suboblique ; peristome strongly crenulated, double; operculum 

 horny, a large central excavated circular space, surrounded by a pale 

 ring, well marked, rising above to the marginal portion. 



Size: maj. diam. 4'5; alt. axis 1'5 mm. 



The nearest known species allied to this is A. crenatus, of the 

 Khasi Hills, but the ridge behind the aperture in this last lies 

 further back with a short interval ; the peristome is not so 

 strongly crenulate. A. pUctochcilus of Darjiling is a much 

 smaller form. 



7. Alycjeds dohertyi, n. sp. 



Localitij. Momeit, Burmah ( W. Doherty, in coll. Aldrich). 



Shell globosely turbinate, solid, not umbilicated ; sculpture 

 regular distant sliarp costulation, closer and fine near the sutural 

 tube ; colour stone, with pink apex ; spire rather high, conoid, 

 rounded, apex blunt; suture impressed, the tube fine, rather long ; 

 whorls 4^, the last swollen, constricted with a rounded ridge 

 midway between the sutural tube and the peristome ; aperture 

 expanded, ovate ; peristome double, fine sharp crenulations on the 

 outer margin, rouuded on the inner. 



Size : maj. diam. 3-25 ; alt. axis 2-8 mm. 



This is quite a new form, partaking in the constriction and 

 peristome of the characters of A. plectocfieilus, crenatus, &c. Momeit 

 lies N.N.E. of Mandalay, about midway between it and Bhamo 

 and further east than Mogok in the Euby Mine District. 



8. ALTCiETTS BUSBTI, n. Sp. 



Locality. Nicobars {G. Busby, in coll. Dr. Hungerford). 



Shell turbinate, of tumid form, widely umbilicated ; sculpture 

 smooth, fine ribbing near the sutural tube and still finer below ; 

 colour pale ochraceous ; spire moderately high, apex blunt ; suture 

 deep, the sutural tube short and thick ; whorls 4|, very rounded, 

 the last much swollen and compressed within the umbilical cavity, 

 constriction simple, slight ; aperture oblique circular ; peristome 

 double, the outer lip flat and expanding at right-angles to the 

 whorl. 



Size : maj. diam. 7"o ; alt. axis 3*0 mm. 



This is the largest species as yet known from the Nicobar 

 Islands. I name it after its discoverer, who gave the specimen to 

 Dr. Hungerford ; its exact locality has not been recorded. 



