788 GASTROPODA. [Pulmoitata. 



inre of the post-embryonic whorls consisting of somewhat irregular, 

 oblique, rather close radiate striae, crossed by indistinct spiral lines. 

 Colour olive-horny, very often with fuscous radial streaks. Epidermis 

 thin, transparent, polished. Spire slightly elevated, rather convex. 

 Protoconch of 1| smooth and convex volutions. Whorls 3, rather 

 convex, rapidly increasing, the last subdepressed, not descending 

 anteriorly, dilated ; periphery and base rounded. Suture impressed. 

 Aperture diagonal, sublunately rotund. Peristome simple, thin, 

 margins approaching, epidermis slightly inflexed. Columella short, 

 oblique, slight!;/ expanded above. Umbilicus wide, perspective, one- 

 quarter of the major diameter. 



Diameter Maj., 4mm. ; rnin., 3-25 mm. : height, 1-7 mm. (type). 



Animal "in! .lualomy. Murdoch, P. Mai. S., iv, 168, pi. 17. f. 1-4. 



Dentition. Hutton, T.N.Z.I., xvi. 172, pi. 9, f. E. 



The anim.al is whitish in colour, with narrow grey lines radiating 

 to the foot-margin ; tentacles darker ; foot somewhat narrow, thrown 

 into minute undulations when the animal is in motion ; mantle slightly 

 projecting over the peristome of the shell. The mouth or lips minutely 

 crenulated ; this allows for considerable distension, and permits the 

 odontophore to be much protruded. 



The buccal mass is large and cylindrical, the posterior end curved 

 down and forward : the salivary gland, dark in colour, is composed of 

 2 lobes, but the cohesion of the two is so intimate that it may be con- 

 sidered a single median gland. 



The radula has the formula 9 + + 9 ; the teeth, disposed in 

 numerous transverse rows which form an obtuse angle, are all aculeate, 

 robust, and smooth, the second one being the largest, from this outward 

 gradually getting smaller. The absence of a central tooth leaves a 

 wide rhachidian cleft. The radula described by Hutton has the teeth 

 increasing in size from the first to the fifth, and then decreasing. 



The reproductive organs are simple. Verge with the retractor 

 muscle at the posterior end ; the vas deferns enters a little below the 

 apex, and forms a short slender tube. The sperniatheca is small and 

 pear-shaped, resting on a short narrow neck ; it is situate at the 

 posterior end of the free oviduct. 



The nervous system is very similar to that of Rhytidc. 



Type in the British Museum. 



Hob. North Island : Parua Bay. \Vliangarei (Musson) : Chicken 

 Island (C. Cooper) ; Mokohinau Islands (Lady Brown) ; Little Barrier 

 Island (Adams) : Motutapu Island (A. Suter) ; Waiheke Island (H. S.) ; 

 Hillyer's Creek ; Mount Wellington lava-fields (Musson) ; Auckland, 

 type (Greenwood) ; Hunua Range (Major Broun) ; Tuakau ; Wai- 

 rangi, \Vaika to (A. Suter) ; bush near Waitomo Caves (A. Hamilton) ; 

 Tarukenga (Major Brow) : Ruatahuna (E. Best) : Forty-mile Bush 

 (FT. S.). 



