428 Transactions. 



The anatomy of this species is said to differ little from that of other 

 " Acmaeas." I do not agree with this, as the shell characters differ extra- 

 ordinarily, and in habits this species is no " Acmaea " : its habitat and rapid 

 movements are unique in the family, if it be classed correctly. 



Notoacmea gen. nov. [P. 71.] 



I name as type Patello'ida pileopsis Quoy and Gaimard, and would class 

 under this genus the remaining uncharacterized Neozelanic " Acmaeas," 

 with the proviso that probably more than one generic form is here confused. 

 The type shell conchologically resembles that of Tectum, of the Northern 

 Hemisphere, and the southern shells were so placed by Thiele, though 

 differences in the radula were shown. The small "Acmaeas," such as 

 A. daedala Suter and A. parviconoidea Suter, are easily separated, and might 

 form a subgenus, for which I propose the new name Parvacmea, and name 

 A. daedala Suter as type. 



If the Neozelanic species were collected and examined in connection 

 with the names here proposed it would at once be seen how natural my 

 groups are, and also that the Australian forms fall into order. 



Patelloida (Quoy and Gaimard, 1834). [P. 73.] 



The nomination of some shells from the Montebello Islands, Western 

 Australia, allowed me the opportunity of rectifying the nomenclature of the 

 shells grouped about A. saccharina (Linne), and I discovered that this name 

 was applicable to the group named by Suter as Collisellina Dall, 1871. 

 The type of Patello'ida Quoy and Gaimard was given in the Manual Conch, 

 by Pilsbry as P. fragilis Q. & G., but that was an error; also one which 

 would not be easily discovered by the Neozelanic worker. These facts were 

 recorded in the Proc. Zool. Soc. (Lond.), 1914, p. 670. 



The Neozelanic species would bs named Patelloida stella (Lesson, 1831) ; 

 P. pseudocorticata (Iredale, 1908) ; P. perplexa (Pilsbry, 1891). 



I will discuss the status of corticata, now admitted as a subspecies, and 

 pseudocorticata in my next communication, when I will give figures eluci- 

 dating my species. 



Notoacmea suteri nom. nov. [P. 65.] 

 Acmaea roseoradiata Suter, 1907, is preoccupied by the prior Acmaea 

 roseoradiata E. A. Smith (Journ. Conch., vol. x, p. 106, pi. i, fig. 19, 1901). 

 I had intended that such alterations should have been made by Mr. Suter 

 himself, but as he has written me to the effect that he will be unable, to give 

 more attention to the Recent Mollusca in the future I herewith propose 

 amendments. Mr. Suter comments : ' This pretty little shell is well cha- 

 racterized, and quite distinct from all other known New Zealand species 

 of the genus." I therefore introduce the above as a suitable alternative. 

 I do not, however, class the species in my genus Radiacmea, though Suter 

 associated it with A. cingulata Hutton. The radular characters are un- 

 known, and the shell differs appreciably to me from Radiacmea. Its reference 

 to Notoacmea is, however, of a temporary character. 



Notoacmea helmsi (E. A. Smith, 1894). [P. 69.] 



Under this name I include the shells referred to Acmaea septiformis 

 Quoy and Gaimard by Suter, and also class as a variant the var. leucoma 

 Suter, 1907, which he referred to A. parviconoidea. Only two localities 



