Webster. — On some Neio Species of Shells. 279 



Rissoina (Eatoniella) olivacea, Hutt. Fig. 9, a. 



I examined the radulae of many typical dark-green and also 

 brown specimens of this shell, further also of the purple-black 

 shells with white sutural band called R. annulata, Hutt. I find 

 radula and operculum identical in all. I consider therefore that 

 R. annulata intergrades with R. olivacea. With Professor Hut- 

 ton's concurrence I propose for R. annulata varietal rank, thus : 

 Rissoina (Eatoniella) olivacea, Hutt. (1882) ; Rissoina (Eatoniella) 

 var. annulata, Hutt. (1884). 



Rissoina agrestis ( = clumsy), n. sp. Fig. 10, a, b. 



Shell solid, imperforate, dull, of a purple-brown shading to 

 cream-colour on the body-whorl. Whorls 5^, including a 2|- 

 whorled domed striato-punctate protoconch with a well-defined 

 convex channel at the suture. The three lower whorls are longi- 

 tudinally, slightly diagonally, rudely ribbed, the channel being 

 ribbed independently. Aperture somewhat angled behind and 

 rounded in front, very thick. Columella vertical, marked by 

 a white shining stripe. Animal unknown. Length, 1^ mm. ; 

 breadth, f mm. 



Hob. Takapuna. 



Type in my collection. 



Very like the illustration of Rissoa impressa, Hutt. 



Eulimella coena (= ordinary), n. sp. Fig. 11, a. 



Shell elongated, slender, white, smooth, imperforate, whorls 7, 

 flat with a blunt heterostrophe apex. Sculpture none, suture 

 slight, aperture ovate anteriorly, columella vertical and slightly 

 twisted. Height, 2J mm. ; breadth, 1 mm. Animal and oper- 

 culum unknown. 



Hob. Takapuna. 



Type in my collection. 



Corbula pura (= clean), n. sp. Fig. 12, a. 



Shell white, thin, tinged with pink before and behind the um- 

 bones, which are one-third from the posterior rounded end. The 

 fold is sharp, its outline concave, its anterior end being far in 

 advance of the anterior dorsal margin. Prodissoconch quadrate, 

 plain, slightly eroded, the entire shell lightly but clearly and re- 

 gularly both concentrically and radiately striate, left valve very 

 slightly the larger. Hinge teeth, sinus, and scars, &c, normal. 

 Height, 5 mm. ; breadth, 10 mm. ; depth from valve to valve, 

 3 mm. 



Hab. Dredged in Kangitoto Channel. 



Type in my collection. 



