362 



H. Beklcer- 



from the kuckersite. A complete description can now, therefore, be 

 given. Since my return to Estonia I have found additional examples 

 of the same species ^ and of another species of the same genus among 

 the collections of the Tartu (Dorpat) Museum, which were removed 

 into Russia during the war, and have now been returned. 



I am indebted to Dr. A. M. Davies for reading the manuscript 

 and proofs. I wish to express my thanks to the officers of the British 

 Museum for the use of the Gray collection from the Girvan district. 



:\1- -a' 



Figs. 1-4. — Leptestia musculosa, sp. nov. L' Dorsal valve, X 2. a, posterior 

 adductors ; a', anterior adductors ; d, diductor marks ; pi, hinge-plates. 

 2. Area with cardinal process, X 2. 3. Ventral valve, X 2. a, adductors ; 

 d, diductor marks ; d', accessor}^ diductors. 4. Shell surface, anterior 

 region, X 20. a, surface ; 6, section. Fig. 5. — Leptestia s]).,YentTalva,lve, 

 X 2. 



Leptestia,^ gen. nov. 



Diagnosis. — Valves dorso-ventrally concavo-convex, rounded- 

 quadrangular in outline, widest anteriorly. As distinctive features 

 may be named : — 



(1) The elliptical visceral fields of both valves internally. 



^ Labelled in the collections Leptaena transversalis Wahlenb. 

 - The name is composed of Lept- from leptos ; and estia from Eesti 

 (Estonia). 



