406 Prof. T. E. Jones and Dr. H. B. IToll on the 



As it is possible tliat by development in age tlie small form 

 {fig. 2) might have approximated to the larger form (fig. 3), 

 we' associate them together under the name of Streinda hey- 

 riclnoides — in the first place as having reference to their exhi- 

 biting the concentric ridging of the new genus StrepuJa, and, 

 secondly, a somewhat trilobate form like some Beyricliice. 



In both cases (figs. 2 and 3) the dorsal edge view is like 

 that of a three-lobed BeyricMa. 



Sir. heyrichioides is rare in the Smith Coll., no. llg,*, Lin- 

 coln Hill, Ironbridge ; and Vine Coll. LXVin, Tickwood Beds ; 

 LXViiu, Tickwood Beds. 



4. Bollia t Vinei, sp. nov. (PI. XIII. fig. 14.) 



Proportions : — L. 10. H. 6. 



Carapace-valve small, suboblong, with well-curved ventral 

 border ; flattisli and thick ; surface reticulated. The bilobu- 

 lar, semicircular, central ridge is proportionally small, but 

 very dibtinct. The supramarginal ridge is thick, and the 

 meshes of the reticulate sculpture enlarge along a line just 

 within it, forming there a series of pits. There is a specimen 

 fixed on a piece of shell in the Vine Coll. XXXIV3, bed no. 

 37 ; also one specimen in the Smith Coll. no. SSg, Woolhope. 



4*. BoUia Vinei, var. mitis, nov. (PI. XIII. fig. 13.) 



Proportions : — L. 11. H. 6. 



This little oblong valve is slightly longer in proportion than 

 JB. Vinei, and the outer of the two curved ridges is within the 

 margin and less pronounced ; the sculpture also is weaker 

 and more uniform. There is another specimen in which these 

 features are still less pronounced, but they are essentially the 

 same as in the foregoing B. Vinei. Vine Coll. xxxiv,, 

 bed no. 37. 



Among the small figures of Silurian Entomostraca from 

 Scandinavia in pi. v. illustrating K. Haupt's " Die Fauna 

 des Graptolithen-Gesteines," &c,, in vol. liv, of the ' Neues 

 Lausitzisches Magazin ' (8vo, Gorlitz, 1878), there are two 

 that look like Bollia at first sight, namely figs. 9 a, J ; but 

 they appear to have a small subcentral lobe low down within 

 the curved ridge. The specimens seem to have been about 

 2 millim. long. Fig. 11 also in the same plate may possibly 

 illustrate an allied form, but no curved ridge is visible. This 



t For Bollia see Ann. & Mag. Nat. Hist, for April 1886, p. 360. 



