180 Systematic Paleontology — Middle Devonian 



Cryptonella (?) lincklaevi Hall, 1867, Pal. N. Y., vol. iv, p. 397, pi. Ix, flgs. 



49-65. 

 Terebratula lincklaeni Hall, 1867, Pal. N. Y., vol. iv. Corrigenda. 

 Eunella lincklaeni Hall and Clarke, 1893, Pal. N. Y., vol. viii, pt. ii, p. 290, 



pi. Ixxx, flgs. 28-32. 

 Eunella lincklaeni Schuchert, 1897, Bull. U. S. Geol. Surv., No. 87, p. 223. 

 Eunella lincklaeni Grabau and Shimer, 1909, N. Am. Index Fossils, vol. i, 



p. 303, fig. 378. 



Description.— Shell ovate or subelliptical, usually broader below the 

 middle, vai7ing from moderately convex to gibbous and sometimes sub- 

 cylindrical; front rounded, subtruncate, or a little depressed. Ventral 

 valve sometimes a little flattened towards the front or marked by a narrov/ 

 mesial depression; beak more or less abruptly incui-ved and truncate by a 

 foramen of moderate size. Dorsal valve with the greatest convexity about 

 the middle of the length, and thence curving regularly to the sides and 

 base. Surface marked by fine concentiic striae of growth, which are 

 sometimes crowded together towards the front, causing a thickening of the 

 shell ; shell-structure distinctly punctate. 



The Maryland specimens are all in the condition of rather poorly pre- 

 served internal or external impressions which were found in arenaceous 

 shales. Although crushed and more or less imperfectly preserved the 

 specimens agree fairly well with figures 64 and 65 of pi. Ix, vol. iv. 

 Palaeontology of New York, which represent dorsal and ventral internal 

 impressions of this species, showing in a similar manner the cavities left 

 by the dental and hinge plat^^s and apparently the diverging muscular 

 or vascular lines. One internal impression when magnified shows a rather 

 regular pustulose surface as represented in fig. 22, pi. xv, the pustules 

 being casts of the punctae of the shell structure. Dr. E. E. Cumings 

 of Indiana University examined this specimen with great care under 

 enlargements from 5 to 85 diameters and found this delineation to be 

 correct. He also examined very perfectly preserved shells in the Yale 

 University Museum and stated that he got " precisely similar appearance 

 with similar preservation." He also reported that " the outer surface 

 of the shell in Eunella appears minutely pustulose, owing to the elevation 

 of the mouth of the punctae." 



Length, 19 mm.; width, 13 mm. 



