29G Systematic Paleontology 



interior characters are rather those of Lingula than Crania. It must be 

 admitted that Pholidops and Lingulapholis have characters that more 

 strongly suggest the Atremata than the Neotremata, but until the early 

 shell stages of living Crania are known it does not seem that a satis- 

 factory phyletic disposition can be made of them. 



LlNGULAriLOLIS TEIIMINALIS (Hall) 



Plate LIII, Figs. 14-19 



Pholidops terminalis Hall, 1859, Nat. Hist. N. Y., Pal., vol. ili, p. 490, pi. ciii&, 



figs. 8a-Sd, 1861. 

 Pholidops arenaria Hall, 18G7, Nat. Hist. N. Y., Pal., vol. iv, pp. 32, 413, pi. iii, 



fig. 3 (fide Clarke). 

 Pholidops terminalis Hall and Clarke, 1892, ibidem, vol. viii, pt. 1, p. 157. 

 Pholidops terminalis Clarke, 1900, Mem. N. Y. State Mus., vol. iii. No. 3, p. 59, 



pi. viii, figs. 23-25. 



Description. — " Shell subelliptical, broader behind, and narrowing to 

 the apex : apex terminal. Surface marked by strong squamiform lamellae : 

 a flattened subtriangular space beneath the apex; the inner margins of 

 the shell somewhat flattened. The muscular impression is double, and 

 situated on each side of a mesial ridge, which becomes thickened and ex- 

 panded towards the apex." Hall, 1859. 



To the above description may be added that both beaks are terminal, 

 protruding nearly equally, and are separated from one another by an in- 

 tervening lamellose thickening of the valves. The growth lines are as in 

 Lingula and not as in most species of Pholidops, where the beak is situa- 

 ated near the middle of the shell with the lines regularly disposed around 

 it, as in the dorsal valve of Orbiculoidea. 



Casts of the interior, especially of small specimens, are difficult to dis- 

 tinguish from associated species of Pholidops, unless the cast is very good 

 and shows the posterior lamellose false area. 



Length 8 mm. to 20 mm. ; width 5 mm. to 16 mm. 



Occurrence. — Oriskany Formation, Eidgely Member. Cumberland, 

 North Branch, Maryland ; Warren Point, Pennsylvania. 



Collection. — Yale University. 



