Manchester Memoirs ; Vol. Ixii. (19 17) 93 



218. Cristellaria rotulata, (Lamarck.) 



Leniiculites rotulata, Lamarck, 1804, Arm. Mus., vol. V. p. 188, 

 No. 3; and T. Encyc. Method., pi. CCCCLXVI, fig. 5. 



Crist ellaria rotulata, Brady, 1884, Chall. Rep., vol. TX, p. 547, 

 pi. LXIX. fig. 13a, b. 



This species is common throughout the Marl and some- 

 times attains a large size. One specimen has been found which 

 measures 3/i6ths of an inch on its largest diameter. 



219. Cristellaria rotulata var. macrodiscus, Reuss. 



Cristellaria macrodiscus, Reuss, 1862 (1863), Sitz. k. Ak. Wiss. 



Wien, vol. XLVI, (1), p. 78, pi. IX, fig. 5. 

 C. rotulata, var. macrodiscus, Chapman, 1896, Journ. Roy. 



Micr. Soc, p. 6, pi. I, fig. 9a, b. 



This variety is not so frequent as the type and it is not 

 always easy to separate from it. Chapman has well noted the 

 chief characteristics of the variety, but I may add that in these 

 Gatherings it is distinguished from C. rotulata by its compact 

 and robust build, as well as by the characters on which the 

 variety was founded by Reuss. In conclusion I desire to say 

 I am in agreement with Chapman in considering the form as 

 only a variety of C. rotulata. 



(There seems nothing to be gained by separating this 

 variety from the type.) 



220. Cristellaria cultrata, (Montfort.) 



Robulus cultratus, Montfort, 1808, Conch. Syst., vol. 1, p. 215, 



54 genre. 

 Cristellaria cultrata, Bradv, 1884, Chall. Rep., vol. IX, p. 550, 



pi. LXX, figs. 4-8. 



Common in all my Gatherings, but most frequent towards 

 the top of the Marl Beds. 



(The carina does not attain any pronounced growth except 

 at Gatherings 2 and 7.) 



221. Cristellaria cultrata. var. sternalis, Berthelin. 



Cristellaria st emails, Berthelin, 1880, Mem. Soc. Geol., France 

 [3j, vol. 1, p. 51, pi. Ill, (XXVI), fig. 2a, b. 



C. sternalis, Chapman, 1896, Tourn. Roy. Micr. Soc, p. 8, pi. 

 II. , fig. ia, b. 



