244 



PHOCEEDINGS OF THK MALACOLOGICAL SOCIKTV. 



There is a variety prodiicta, Nevill, from Annesley Bay (W. T. 

 Blaiiford). These last two species arc probably identical ; I do not 

 unite tliem, as I have not seen authentic specimens. 



Hah. — Arabia (Wilke), Massau, etc. (Jickeli), Nossi-Comba (Marie). 



Fig. 1. Plecotrema punciostriatum. 



,, 2. • monilifera. 



,, 3. bicolor. 



,, 4. punctigcrum. 



,, 5. decussatum. 



These figures are drawn from specimens on the type tablets of the Cumingian 

 Collection in the British Museum (Natural Ilistorj'). 



12. P. typicum, H. and A. Adams. Troc. Zool. Soc. 1853 (1854), 

 p. 120. 



The synonymy, in my opinion, includes both P. liratum and P. con- 

 cinnmn, -which were described in the same paper as P. fypicnm; they 

 appear only to vary in the size of the umbilicus, which is not even 

 constant in the type tablet of P. typicum. Mr. Brazier has suggested 

 that they may be forms of P. octanfradum, but from the specimens 

 I have seen I shoidd place them here. 



Hah. — Pulo Penang (Mus. Cuming), I. of Sibuyan, Cagayan, 

 I. of Mindanao, etc. (Hidalgo), New Caledonia (Gassies) ; as P. 

 liratum, Moreton Bay (Mus. Cuming), New Caledonia and Savage Is. 

 (Brenchley) ; as P. concirnuim, Moreton Bay (Mus. Cuming), Port 

 Jackson, Tambourine Bay, Hunters Bay, Bantry Bay (Brazier), Borneo 

 (Everett). 



