168 ON PERMIAN ENTOMOSTRACA FROM 



in plate X., but define more clearly tlie features of the anterior 

 extremity with its compressed edge, and the dorsal surface with 

 its hinge-line. We must remember that it is only a cast that 

 we have before us ; Mr. Kirkby has collected several specimens 

 of casts with portions of the valves attached, and these remind 

 us that possibly the profile of the carapace itself differs some- 

 what from that of the cast, especially as regards the attenuated 

 margins. 



6. C. suB-RENiFORMis, Kirhhif. PI. XI., figs. 23a — 2?>d. 

 These figures are intended more especially to define with 



accuracy the dorsal overlap in this interesting species. (See 

 p. 155.) 



7. C. JoNESiANA, Kirkby. PI. XI., figs. 24a — 24cZ, and 25a — 



25fZ. 

 Here also the artist has given his best attention to the careful 

 delineation of the features shown in the hinge-line of this species , 

 and its smaller variety. (See p 153.) 



EXPLANATION Or PLATE YIII. 



Excepting figs. Ic, 2c, 5^, 5/, 85, 9a, and 95, the figures are magnified 25 diame- 

 ters. The specimens are from Tunstall Hill, excepting figs. 6-9. 



Fig. la Kirhhya Permiana, Jones : left valve. 



lb „ ,, lateral contour, dorsal aspect. 



Ic „ „ reticulation around the oval spot, magnified 50 



diameters. 



Id „ „ lateral contour, ventral aspect. 



le „ „ lateral contour, end-view. 



2a „ ,, right valve. 



2b „ „ right valve, dorsal aspect. 



2c „ „ oval spot and reticulation, magnified 50 diameters. 



2d „ „ right valve, ventral aspect. 



2e „ „ right valve, lateral contour, end-view. 



3 „ „ right valve, inner aspect. 



4 „ „ var. glypta, Jones : right valve. 

 5a „ „ right valve. 



