14(5 ON PERMIAN ENTOMOSTRACA FROM 



B. PLEBEiA, var. Reussiana. pi. IX., fig. 6; woodcut 8. 



B. Reussiana^ Kirkby. " Ann. Nat. His.," 3rd ser., 

 vol. ii., p. 326, pi. X., fig. 6. 

 Carapace siib-reniform ; dorsal margia flatly convex ; ventral 

 margin sinnated near the centre ; postero-dorsal region 

 abruptly sloping; antero-dorsal region forming a slightly 

 convex slope; anterior extremity truncated rather diag- 

 onally ; lateral contour compressed centrally. 

 Although the var. Reussiana differs from B. plebeia proper^ 

 and most of its varieties, in its sinuate ventral margin, compara- 

 tively blunt and high beak, less prominent dorsal margin, and 

 consequently greater length compared with its height, and in its 

 compressed lenticular lateral contour, yet the varieties Neptuni 

 and elongata link it so closely with B. j^lebeia, and its variety 

 caiidata^ that I prefer to follow Mr. Jones' advice, and regard it 

 as a variety, rather than to keep it distinct as a species. 



B. plebeia, var. ventricosa. PI. IX., fig. 3; woodcut 9. 



B. ventricosa, Kirkby. " Ann. Nat. His.," 3rd ser., 

 vol. ii., p. 326, pi. X., fig. 3. 

 Carapace sub-rhomboidal, ventricose ; dorsal margin flatly 

 convex; ventral margin slightly sinuous; postero-dorsal 

 region abruptly sloping, concave; antero-dorsal region 

 sloping rather less abruptly, convex; anterior extremity 

 diagonally truncated, angulate above, rounded below ; 

 posterior extremity bluntly pointed ; lateral contour lenti- 

 cular, ventricose. 

 I am deterred by Mr. Jones' advice from considering that the 

 ventricosity, blunt produced posterior extremity, and angulated 

 anterior extremity, can essentially separate this form from 

 Reussiana, Neptuni, and other varieties of B. plebeia. 



This variety is common at Tunstall Hill. A single speci- 

 men occurred to me at Moorhouse, Yorkshire. 



