Palceozoic Bivalved Entomosfraca. 267 



incurved ; anterior extremity high and truncated inwardly • 

 posterior extremity acute, rostrate ; lateral contour elliptical, 

 widest just in front of centre ; surface smooth. Length 2V inch. 



This is probably the same species as that represented by 

 fig. 7, pi. xxxii., in our paper on Bairdia *. Its nearest 

 allies seem to be B. amputata^ K., B. nitida^ J. & K., and 

 B. submucronata, J. & K., when ranging beyond their typical 

 forms. 



Localities. In Carboniferous-Limestone series, at Cowden 

 Quarry, Fifeshire ; in Yoredale rocks, at Gleaston Castle, 

 Lancashire; in Scar Limestone, at Arnside and Sandside, 

 Westmoreland. 



44. Bairdia suhelonqata^ J. & K., var. major. 

 (PL iX. %. 14.) 



This is a very large Bairdia, somewhat crushed by pres- 

 sure. It has rather the shape that a big B. suhelongata might 

 take if squeezed flat, and we put it as a variety of that species. 



It is about i inch in length, elongate, with straight dorsal 

 and ventral borders, with the anterior extremity high and 

 evenly rounded, and the posterior low and subacute ; the sur- 

 face is smooth. 



It occurs in the Carboniferous- Limestone series at Barmoor 

 Rcdhouse (Lowick), Northumberland. 



As intimated at the beginning of this paper, the foregoing 

 descriptions of species are necessarily very brief and rather 

 incomplete. In some cases little more can be said until the 

 species shall have been better known. With other species 

 we have already material enough to allow of fuller accounts 

 being given, and this we hope by-and-by to do, either in 

 these pages or elsewhere. 



It will have been seen how much we are indebted to various 

 friends for assistance in specimens ; and though their names 

 have been repeatedly mentioned in this and former pages, we 

 must again express our thanks, especially to our old friends 

 Mr. John Young, of the Hunterian Museum, Glasgow, and 

 Mr. James Bennie, of the Geological Survey, Edinburgh. 



EXPLANATION OF THE PLATES. 

 Plate VI. 



[All the figures magnified about 25 diameters.] 

 Fig. 1. Bythocypris Phillipsiana, .J. & 11., var. carhonicct, J. & K. a, rig-lit 

 valve ; b, end view. 



* Quart. Journ. Geol. Soc. 1879, vol. xxxv. p. 565, 



18* 



