Manchester Memoirs, Vol. Ixii. (19 17) ill 



angle of the chambers in respect to the vertical axis of the shell, 

 the evolution of the conical form of the mature test from the 

 lenticular shape of the young - shell. 



This species is rarer than the preceding one, only half the 

 number of specimens being noted from six Gatherings of Marl. 



I have much pleasure in associating Mr. F. Chapman's 

 name with this interesting form, in grateful remembrance of the 

 valuable assistance he has so willingly afforded me in overcom- 

 ing the difficulties which I have encountered in my work on the 

 collections now under consideration. 



(Halkyard's intention of naming this new species after 

 Frederick Chapman cannot unfortunately be carried out, inas- 

 much as the form has already been described and figured as 

 above, though Liebus misunderstood the structure of the test 

 and referred his specimens to the genus Cymbalopora of Hage- 

 now. In this species there is a limited amount of thickening 

 of the shell wall on the superior side, thus perhaps affording 

 evidence of some relationship between Linderina and the new 

 genus Halkyardia, but the superior thickening is very limited 

 in extent and is as coarsely perforate as on the inferior side. 

 The species is absolutely indistinguishable from depressed 

 specimens of Cymbalopora poeyi, (d'Orb.) when viewed from 

 the superior surface.) 



Genus Discorbina, Parker & Jones. 

 267. Discorbina obtusa, (d'Orbigny.) 



Rosalina obtusa, d'Orbigny, 1846, Foram. Foss. Vienne, p. 179, 



pi. XI, figs. 4-6. 

 Discorbina obtusa, Brady, 1884, Chall. Rep., Vol. IX, p. 644, 



pi. XCI, fig. 9a, b, c? 



The specimens found in my collections are both small and 

 rare. 



268. Discorbina allomorphinoides, (Reuss.) 



Valvulina allomorphinoides, Reuss, i860, Sitz. k. Ak. Wiss. 



Wien. vol. XL, p. 223, pi. XI, fig. 6, a-c. 

 Discorbina allomorphinoides, Brady, 1884, Chall. Rep., vol. 



IX, p. 654, pi, XCI, figs. 5, 8. 



This species is more frequent than D. obtusa and attains 

 somewhat larger dimensions, though it can hardly be said to be 

 very well developed in the Blue Marl. 



