HEL1X-CALYMNA. 75 



Amphidoxa (Calymna) feredayi SUT., Tr. N. Z. Inst. 1890, p. 91, 

 t. 18, f. 10 a, b (shell), Q, R (dentition and jaw). 



G. OLIVACEA Suter. PI. 22, gs. 61, 62, 63. 



Shell glohosely depressed, perforated, shining, pale yellow-olive, 

 without markings, thin and transparent, with very close-set arcu- 

 ated ribs, which are flatly rounded, about 10 per mm., interrupted on 

 the surface with several distinct spiral grooves. Spire slightly ele- 

 vated, obtuse; apex smooth. Whorls 3, rather rapidly increasing, 

 rounded, the last slightly flattened on the surface, rounded on the base. 

 Suture deep. Aperture oblique, rotundly ovate, slightly excavated 

 by the penultimate whorl. Peristome very thin, straight, regularly 

 arched, the upper part advancing. Columellar margin not reflected, 

 sharp, vertically slightly arcuated ; outer margin strongly arched, 

 the margins approximating. Umbilicus very narrow, not deep; 

 umbilical region infundibuliform, faintly striated. 



Alt. 3, greater diam. 5, lesser 4 mill. (Suter.) 



Hilly er's Creek, near Auckland, N. Z. 



Amphidoxa (Calymna) olivacea SUTER, Tr. N. Z. Inst. 1891, p. 

 290, t. 21, f. 13 a, b (shell), 14, 15 (jaw and dentition). 



B. Shell smooth, polished. 



G. OMEGA Pfr. (H. compressivoluta Rv.). Vol. I, p. 128. 

 G. CORNEA Hutton. PI. 22, figs. 64, 65, 66. 



Shell thin, depressed, imperforate, striated, translucent; color 

 pale horny. Spire slightly convex ; whorls 2 , rapidly increasing, 

 rounded, smooth, polished, finely striated with growth lines; suture 

 impressed ; aperture very oblique, transversely oval ; peristome thin, 

 regularly arched, columellar lip slightly reflected. Greatest diam- 

 eter 0-25, least 0'2. Dentition 17-1-17. 



From A. compressivoluta this shell may be distinguished by the 

 whorls being convex instead of flattened ; from the other New 

 Zealand species of Amphidoxa by being imperforate, and of a pale 

 horny color without markings and without ribs. The mantle of the 

 animal is marbled with black, which shows through the shell. 

 (Hutt) 



Auckland, N. Z. 



Amphidoxa cornea HUTTON, Trans. N. Z. Inst. xv, p. 136, 1882 ; 

 I.e., 1883, p. 171, t. 10, f. A (dentition). 



My figures were drawn by Mr. Suter from Prof. Button's type. 



