PLATE 45. 



Page 



Pig. 1. Merista ( = Meristella), species undetermined. 252 



This species, of the size of 1 a and more rarely of 1 b, c, occurs in considerable numbers in 

 the Upper Pentamerus limestone, and 1 d has the same form and proportions; but I have 

 not been able to determine fully its relations to the other species described, or whether it 

 may be the extreme young of itf. princeps. 



Fig. 2 a - p. Henssel^ria mutabilis. 254 



2 o, b. Dorsal and profile views of a young specimen. 

  2 c. Dorsal view of a large specimen, where the beak is scarcely incurved. 

 2 d, e,f, g. Specimens presenting the ordinary characters of the species. 

 2 h, i. Dorsal and profile views of a more elongated form, which is slightly wider towards the 



upper part of the shell. 

 2 fc, I, m. Dorsal, profile and front views of a very gibbous specimen. 



2 n, 0, p. Views of specimens which are much broader towards the upper part of the shell, 

 very gibbous, and having the beak closely incurved. 



Fig. 3 a - g'. Renssel-sikia jEquiradiata. 255 



8 a, b, c. Dorsal, ventral and profile views of a large specimen, which is proportionally longer 



tlian the prevailing forms. 

 3 d. Front view of the same. 

 3 e,f,g. Dorsal, ventral and front views of a larger specimen, which has a proportionally 



greater breadth than the preceding. 



Fig. 4. Renssel.^ria elliptica. 256 



i a. b, c. Dorsal, profile and front views of the same specimen. 



