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



placed it, as this genus is said to be viviparous. In the exterior 

 of the animals of Paryj)hanta and Rhytida there is hardly any 

 difference, and the shell characters of P. Meesoni, the smallest 

 known of the genus, are as well with Rhytida as with Paryphanta. 

 It is remarkable for the absence of a thick epidermis involving 

 the peristome. 



Thalassohelix zigzag, Gould, sp. 



I am glad to say that I was perfectly right in admitting T. 

 ziczac, Gould, and T. p)ortia, Gray, to be one and the same species. 

 I sent a specimen to Dr. W, H. Dall in Washington to have it 

 compared with Gould's ziczac and he kindly wrote to me that 

 there is no doubt whatever of the identity of my specimen with 

 Helix ziczac, Gould. A similar specimen was sent to Mr. E. A. 

 Smith of the British Museum and this gentleman most obligingly 

 informed me that it perfectly corresponds with Gray's Helix portia. 



Thalassohelix zelandi^. Gray, sp. 



A specimen of this shell from Auckland w^as also forwarded to 

 the British Museum for comparison with Gray's type. I am 

 indebted to ISIr. E. A. Smith for the following report : " The shell 

 under this name is, I think, a form of that species. It is larger 

 than any of our typical examples and more brightly variegated, 

 and the whorls are perhaps a trifle flatter ; still I think it is only 

 a variety." 



Allodiscus wairoaensis, n,sp. 

 (PI. XXII. figs. Z-Zh.) 



Shell small, discoidal, perforated ; colour pale horny with radiate 

 streaks of rufous on the surface, tessellated on the periphery, 

 minutely spotted on the base; not shining, thin, semi-transparent, 

 with fine and narrow radiate ribs, which are almost straight on 

 the surface, slightly sinuated at the side and straight again on 

 the base, extending to the umbilicus. Ribs about 7 per millm. 

 Spire very short, flat. Whorls 4|^, rounded, slowly and regularly 

 Apex blunt, smooth. Suture impressed, the last 



