MOLLUSCA or IMlTA. 367 



sharply constricted, enlarging suddenly into a high sharp ridge, 

 across the whorl, flattened in front and expanding to the aperture, 

 -which is nearly circular ; peristome double, the inner lip thickened, 

 the outer less so, the shelly layers are seen overlapping each other 

 when viewed from the left side. 



Size : maj. diam. 3-0; alt. axis 1-3 mm. 



This species was found near the furthest point as yet surveyed 

 up the Tsanspu (1913) or about 150 miles up the lliver from 

 Pasighat, 



Altc^tjs panggiana, n. sp. (Plate CLVI. figs. 3, 3 a.) No. 3143 

 B.M. Coll. 



Locality. Sibbum, Abor Hills (Lt. G. F. T. Oal-es, R.E.). Only 

 a single specimen received. 



Shell openly umbilicated, globosely conical, sculpture, fine; close 

 costulation next the sutural tube, succeeded by much stronger 

 and more distant, towards the apex becoming very fine ; colour 

 whitish ; spire moderately high, apex small ; suture moderately 

 impressed ; whorls 4, well rounded, the last smooth and straight 

 from sutural tube to the aperture ; aperture circular ; peristorne 

 well rounded on the inner margin, well crenulated on the outer in 

 5 folds ; operculum multispiral, sutures distant, intermediate space 

 diagonally striate, with well-marked lines of growth. 



Size : maj. diam. 4 ; alt. axis 1*6 mm. 



I name this species after the Abor Clan Panggi, of which the 

 principal stockaded village is Sibbum. 



The sutural tube is bent on itself in this particular specimen, 

 and must be abnormal, for although I have now handled hundreds 

 of shells of this genus, I have never seen one like it before. 



Alvc^us sibbumensis, n. sp. (Plate CLVI. figs. 4, 4 «.) 

 No. 3142 B.M. Coll. 



Locality. Sibbum, Abor Hills {Lt. G. F. T. Gales, B.E.). 



Shell globosely conoid, solid, well umbilicated ; sculpture : very 

 fine, close transverse costulation near apex, becoming more distant 

 on the 3rd whorl, extremely fine and close next the long sutitral 

 tube ; there is an indication of distant longitudinal liration also at 

 this part; a few distant indistinct lirae cross the smooth portion in 

 front of the constriction ; colour whitish stone ; spire fairly high ; 

 suture well impressed ; whorls 4, sides well rounded, the last very 

 tumid; aperture nearly circular, snbvertical on the columellar 

 side ; peristome doiTble, very much thickened on the outer margin, 

 less so on the inner. 



Size : maj. diam. 6-7; alt. axis 3'0 mm. 



The sculpture, particularly that of the swollen portion of tlie 

 last whorl, near the sutural tube, is characteristic of several species 

 of Ahjccei of the Abor Hills. 



