272 CRETACEOUS CRUSTACEA. 



from the lateral angle, having a slight backward curve ; epi- 

 branchial lobe pyriform, tumid^ defined by the meso-branchial 

 sulcus, which extends from the inner third of each side of the 

 nuchal furrow to as far below the cardinal angle on the outer 

 margin as the nuchal furrow is above it ; meta-branchial sulcus 

 on each side forming a sharply impressed line like the others ; 

 all the dorsal surface tumid, except the posterior half of the 

 meso-branchial lobes, and the posterior branchial lobes, which 

 are strongly depressed; surface strongly and closely granu- 

 lated irregularly, the granules being of three or four difi'erent 

 sizes ; a few small tubercles like those on the anterior margin 

 also occur, one being conspicuous on each side, slightly below 

 the middle of the furrow which separates the proto-gastric 

 from the hepatic lobes, and two on each side on the meso- 

 branchial region a little within the middle. Width of cara- 

 pace 10 lines, length b^ lines, transverse length of one orbit 

 \~ line, depth of middle of hepatic region 3 lines. 



The coarsely granular surface easily distinguishes this species 

 from the smooth and glossy B. Buchii, Reuss sp. The anterior 

 lateral margins are also strongly curved. There is a third spe- 

 cies in the University collection at Cambridge, distinguished 

 from the other two by a very fine uniform granulation of the 

 surface, but it is not sufficiently perfect for description ; it might 

 be called R. granulosa. 



Rare in the Upper greensand of Cambridge. 



{Coll. Mr. Carter, Cambridge.) 



Printed by Taylor and Francis, Red Lion Court, Fleet Street. 



