84 



PROCEEDINGS OF THE MALACOLOGICAL SOCIETT. 



Reymondia. Later, in another work (iii), he proposed the families 

 Hylacanthidse, instead of Tiphobidae, for Tiphohia, and Syrnolopsidae 

 for Syrnolopiiis. 



The following table shows at a glance the genera of thalassoid 

 forms which appear to me admissible, also the number of species 

 described, and the number retainable. In considering some of the 

 described species as synonyms, I very likely may have acted rashly, 

 but in most cases I feel pretty confident that the decisions arrived at 

 will eventually be maintained, whenever the opportunity occurs of 

 studying the actual Bourguignat Collection at Geneva. For convenience 

 sake the genera are given alphabetically : — 



The examination of the above table shows that 138 so-called species, 

 distributed in twenty-three genera, have been described, but of these 

 only about fifty-eight should, in my opinion, be retained. 



Nine genera have been described which appear to be synonyms, 

 namely : — 



Nassopsidea, Martens = Edgaria. 

 Nassopsis, Smith = Lavigeria. 

 Ponsoiibya, Ancey = Baizea. 

 Eeymondia, Bourg. = Giraudia. 



Boierguignatia, Giraud = Paramelania. 

 Cambieria, Bourg. = Tanganyicia. 

 Coulboisia, Bourg. = Stanleya. 

 Hauttecxuria, Bourg. = Stanleya, 

 Horea, Smith (preoc.) = Lechaptoisia. 



In the following list all the important references are given, and, in 

 order to economise space, some of the works referred to are indicated 

 by numbers which will be found in the bibliography at the end of 

 the paper. 



I. THALASSOID FOEMS. 

 Chytra Kirkii (Smith). 



Limnotrochus Kirkii, Smith : iii, p. 426 ; ii, p. 286, pi, xxxiii, 



figs. 18-18^; Crosse, p. 128 ; Bourguignat, ii, pi. x, figs. 1-3; 



iii, p. 135; Martens, p. 209, pi. vi, fig. 40. 

 Chytra Kirki, Moore : i, p. 307, pi. xxiii, fig. 6 ; ii, pp. 228-234, 



figs. 11-16, and tigs, on p. 350; Digby, Journ. Linn. Soc, 



1902, vol. xxviii, p. 434, pis. xxxviii-xl. 



