498 THE LAND AND FRESH-WATER MOLLUSCA OF NEW ZEALAND, 



from Ch. buccinella, Reeve. There is no doubt that both species 

 are closely allied, but they are distinct. I compared fresh and 

 good specimens of both, and the result of my investigation is as 

 follows : — In buccinella the inner volutions are slightly elevated 

 above the last, whilst in serpentinula the surface is perfectly flat. 

 In the former the ril)lets are stronger and sharper and consider- 

 ably more directed forwards ; there are about 9 per millm., whilst 

 in seyyentinula they number about 15 per millm. The growth- 

 lines of the interstices are distinctly reticulated in buccinella, but 

 simple in serpentinula. The light-brown colour markings on the 

 latter generally form zigzag lines on the periphery and base, but 

 buccinella is mostly tessellated, horny and chestnut. In buccinella 

 the last whorl is more tapering and the umbilicus slightly narrower 

 than in serpentinula. In both the apex is radiately striated. In 

 the dentition there is no great difference. 



I am of opinion that Ch. serp)entinula should be considered as 

 a variety of Ch. buccinella. 



Charopa anguiculus. Reeve, var. montivaga, n.var. 

 (PI. XXIII. figs. 11-116.) 



\_ = buccinella, Hutton, Suter, non Reeve. 



Shell subdiscoidal, umbilicated, horny or light brown, with 

 radiate irregular broad streaks of fulvous or chestnut ; faintly 

 shining, thin and semitransparent; closely arcuately longitudinally 

 ribbed, riblets 10-11 per millm., interstices with fine growth-lines. 

 Whorls 5, slowly and regularly increasing, rounded ; suture im- 

 pressed ; periphery rounded ; the last whorl not descending in 

 front. Spire almost flat. Embryonic whorl smooth. Aperture 

 diagonal, rounded. Peristome acute, straight, regularly rounded, 

 columellar margin not deflexed, margins approximating. Umbilicus 

 broad, perspective, occupying nearly four-tenths of the diameter. 

 Base rounded. 



Diam., greatest 3J, least 3J ; height \^ millm. 



A short diagnosis is also given in Trans. N.Z. Inst. Yol. xvi. 

 p. 192 {P. bicccinella'). 



