242 mOCEEBINGS OF TUE MALACOLOGICAL SOCIETY. 



sub-g:roup the species ; Pfoiffer attempted to do so and made them 

 into three sections — (a) with the umbilicus open; (b) rather im- 

 perforate ; (c) aberrant species. The border-line between (a) and {b), 

 and tlie use of such a dehnition as (c) I fail to grasp. 



M. Degrange-Touzin, making use of a manuscript name of Dr. 

 Bocttger's, has ' formed a new genus, Proplecotrema, with type 

 /*, marginale, Grat., to contain smooth fossil species. Tliis would 

 also include P. antiquum, P. ovale, P. turbiniforme, and P. conicum. 

 I regard this genus as unnecessary, and so do not recognize it. There 

 is an interesting note on the subject of the absorption of the internal 

 Avhorls by Crosse and Fischer.^ 



The recent species are as follows : — 



1. P. decussatum, II. and A. Adams. Proc. Zool. Soc. 1853 (1854), 

 p. 121. 



Tlicy give the locality as the Philippines, but the tablet has now 

 no label. 



2. P. striatum, Philippi. Zeitsch. fiir Malak. 1846, p. 98. 



The synonyms arc ? Laimodonta striata, Nuttall MS., P. incequaJe, 

 C. B. Ad. MS., P. labreUum, H. and A. Ad. (Proc. Zool. Soc. 1853, 

 p. 122, non Auricula labreUa, Deshayes). 



Ilab. — Sandwich Is. (Nuttall) ; Kapa Is., I. of IS^egros, and Borneo 

 (Mus. Cuming); Oahu (Pease). 



3. P. bicolor, Pfeiffer. Mon. Auric. 1856, p. 104. 



This may prove to be P. striatum, Phil. : from the types, however, it 

 seems to diifer in that its mouth, both by size and position of teeth, 

 is more closed ; the umbilical chink is smaller ; and it has a lighter 

 zone under the periphery, while P. striatum is generally the same 

 colour all over. 



Ilab. — Port Jackson (Mus. Cuming). 



4. P. hirsutum, Garrett. Amer. Joum. Conch, vii. 1872, p. 219. 

 Sab. — Viti Is. (Garrett). Allied to P. striatum, Phil. 



5. P. octanfractum, Jonas. Zeitsch. fiir Malak. 1845, p. 169. 



I place P. clausum, H. and A. Adams (Proc. Zool. Soc. 1853, p. 121), 

 with some doubt as a synonym of this species. There are two tablets 

 labelled P. clausum in the Cuming Collection : one is P. striatum, Phil., 

 and the other P. octanfractum. Of this latter tablet one has been 

 figured by Pfeiffer ^ under the name of P. clausum. Pease records '' 

 P. clausum from Hawaii, and states that his specimens agree rather 

 with the Messrs. Adams' description than Pfeiffer's ; his shells there- 

 fore are probably P. striatum. P. consobrinum, Garrett,* is also a 

 synonym. 



Ilab. — New Caledonia and Savage Is. (Brenchley), Paumotu, Fiji, 

 and Gambler Is. (Garrett), Port Jackson (Brazier), Borneo (Everett), 



' Act. Soc. Linn. Bordeaux, vol. xlv. (1893), p. 157. 



* Journ. de Conch, xxx. (1883) pp. 171-181, j)!. viii. ; abstract iu Jouru. R. 

 Micro. Soc. iv. (1884) pp. 730-731. 



' Novit. Couch, i. p. 15, t. 5, fig-.s. 9-11. 



* Proc. Zool. Soc. 1871, p. 4G9. 



* Troc. Acad. Nat. Sci. I'hilad. 1873, p. 236. 



