SUTER : COMMUNICATIONS FROM NEW ZEALAND. 5 1 



out. Thus Mr. Moss has found a central tooth on the radula oi R. 

 greemvoodi, and there is no doubt about it, as he kindly sent me a photo 

 showing that tooth distinctly. But neither Capt. Hutton nor myself 

 have come across a radula of that species with a rhachidian tooth. 

 Rhytida has a smaller number of teeth in a transverse row, and they 

 only vary from 9 to i8 on each side from the mesial ; the central 

 tooth is usually wanting. It may be of some interest to give here the 

 formulae of the species that have been examined : — 



Rhytida greemvoodi. Gray. 9 — o — 9 to 11 — o — 11 (Hutt.). 



„ ,, II — I — II (Moss.). 



„ paiula, Hutt. 18— 0—18 (Hutt.). 



,, ctfrina, Hutt. 17 — o — 17 (Hutt.). 



„ australis, Hutt. 16 — o — 16 (Hutt.). 



,, meesoni, Sut. 12 — o — 12 (Sut.). 



Species of Paryphanta have as a rule a much larger number of 

 teeth on a transverse row, which of course corresponds in some 

 measure with the much larger size of the animal and the radula, and 

 the number of teeth on each side from the middle varies from 14 to 

 67. A rhachidian tooth is nearly always present. Here follow the 

 formulae of some of the species :— 

 Paryphanta busby i, Gray. 50 — o — 50 (Hutt.). 



„ hochstetteri, Pfr. 67 — i — 67 (Godwin-Austen.). 



,, urnula^ Pfr. 14 — i — 14 (Sut.). 



„ edwardi, Sut. 26 — i — 27 (Sut.). 



,, atramefitaria, Shuttl. 50 — i — 50 (Sut.).(i from Victoria). 



I also examined the radula of P. biisbyi, and saw no trace of a 

 central tooth. When describing the dentition of P. urnula I stated 

 that there was no rhachidian tooth, but I examined the odontophore 

 again and found a central tooth in several places, though the greater 

 part is without it. 



Again Schizoglossa ?io'voseela?idica, Pfr., has according to Hedley no 

 central tooth, the formula being 24 — o — 24, but in a photo taken by 

 Mr. Moss there is a central tooth distinctly visible. 



2.— Abnormities in the Teeth of the Radula of Land Shells. 



( Plate iii, fi.i;s. 2, 3.) 



The first time I came across a very remarkable abnormity in the 

 teeth of the radula was in 1891, in Endodofita varicosa, Pfr., which 

 was figured in '■^ Trans. N'. Zeal. Inst." xxiv, pi. xxii, fig. 29. Since 

 then two more cases came under my notice, one in Phacussa hypopoHa, 

 Pfr. (fig. 2), where the central tooth is unicuspid instead of tricuspid. 



