MOLT.USCA or IXDTA. 421 



graphicus var. It was found that the examples from Teria Ghat 

 (2513 B.M.), at the foot of the Khasi Hills, came nearest to the 

 type, but differences are soon discovered ; in other words, they are 

 not identically the same. When looked at side by side under the 

 microscope, one notices that the sutural tube is shorter, more 

 knob-like, that the costulation is very fine, hair-like and distant, 

 averaging 5 adjacent to the sutural tube. The shell is larger, with 

 the perforation hidden. In the typical Arakan shells this sutural 

 costulation is more concentrated, 6, stronger, lying closer together, 

 while the perforation is seen. I have examined 8 from Teria 

 Ghat; 2 from Cherra Poonjee; 7 from the Garo Hills, 60 miles to 

 the westward of Teria; 9 from the North Khasi scarp, 50 miles 

 to the northward. They are all alike. But when we come to the 

 Lhota Naga Hills, which are about 130 miles from Teria on the 

 north of the range and well inside the drainage of the Assam 

 Valley, variation shows itself, and in No. 2607 (18 examples) and 

 Pikuni Hill, Naga, No. 2602 (7 examples), the sutural tube is 

 short and bulbous, has eight quite strong contiguous lines of costu- 

 lation, followed by the more distant on the rest of the shell. The 

 peristome also shows a slight tendency to firabriation, while the 

 swollen part of the whorl behind it is crossed by two distant lirse. 

 The Pikuni and Lhota Naga shells I distinguish as A. {Cycloryx) 

 variabilis (see back, under No. 6). 



Altc^us ingrami, W. Blf. 



Godwin-Austen, Moll. Ind. vol. i. 1886, pi. xliv. figs. 1-1 c. 

 Typical species figured. Coll. Blf. No. 68.06.4.4 B.M. 

 Locality. Tongoup, Arakan. 



Nevill, Hand-list, p. 292, No. 25. 

 Var. NAGABNsis, Godwin-Austen. 



2 Shengorh, Dafla Hills, G.-A.=mac(jregori, G.-A. 

 20 Burrail, &c., Naga Hills, G.-A. =dlstincttis, G.-A. 

 These have been returned to the Calcutta Museum. 



Altc^us nitjdus, W. Blanford. (Plate CLI. figs. 4, 4rt.) 



Specimen figured. Coll. Blf. No. 54.06.4.4 B.M. 

 W. T. Blanford, J. A. S. B. xxxi. 1862, p. 141. 



Original description : — " Testa anguste umbilicata, depreaaa 

 tiirhinata, solidula, fulvo-cornea, nitida, transluoens. Spira 

 conoidea, laterihus convexis, apice obtusa , sutura impressa. Anfr. 4, 

 convexi, idtimu^ ad peripheriani subangulato compressus, subtus 

 planidato-convexus, ad latxs breviter tumidus, ibidem confcrtisshne 

 costulatus. Spatinm constrictmn longum, nitidum, lira retro-recum- 

 bente, parum elevata, prope regionem injlatum munitum. Tubidum 

 suturate breve. Apertara diagonalis, undata, circularis. Peristoma 

 ad basin antice, superne prope anfractum pemdtimum retro sinu- 

 atuin, duplex ; interno continuo, hreviter porrecto, basi canaliculato ; 



