Maryland Geological Survey 295 



Genus LINGULAPHOLIS n. gen. 



Descriplion. — Pholidops-like brachiopods, but uncemented, with termi- 

 nal beal^s which are separated from one another by a lamellose thickening 

 of the posterior region of the valves, thus producing a false area on each. 

 Valves apparently slightly gaping posteriorly. The solid beaks are un- 

 equally developed, the ventral (?) extended a little beyond the other. 

 Growth lines as in Lingulella or Obolus, {. e.. they pass behind the beak and 

 across the false area. Interior as in PhoHdops. 



Type Pholidops tenninalis Hall. 



The oboloid exterior, with terminal beaks and false areas, and the un- 

 cemented valves distinguish Lingulapholis from Pholidops. To this genus 

 are referred P. terminaUs and P. linguloides Hall.^ The latter species 

 the writer has in his private collection, represented by excellent material 

 etched out of rock from Canandaigua Lake, New York, by Beecher. An- 

 other species is P. calceola Hall and Clarke, of the Onondaga ; probably 

 also P. infrasilurica Huene of the Lower Silurian of Eussia. 



Tlie systematic position of Lingulapholis and Pholidops is uncertain, 

 but most students of Brachiopoda refer the latter to the Craniidae. Lingu- 

 lapholis, however, was not a cemented species like Crania., but had a 

 functional pedicle throughout life, which apparently came from between 

 the slightly gaping valves, as in Lingula. The valves of Pholidops are 

 closely appressed, without false cardinal areas, and do not appear to gape 

 posteriorly. On the other hand, there is unmistakable evidence that the 

 excentric ventral beak of Pholidops was cemented to foreign objects, in 

 which event there would be no use for a pedicle, as is the case in other 

 genera of the Craniidae. On the other hand Huene " points out that the 



^Lingulapholis linguloides (Hall). Pholidops oblata Hall, 1867, Nat. Hist. 

 N. Y., Pal., vol. iv, p. 414, pi. lii, flg. 10 (based on a cast of the interior; there- 

 fore not expressive of the species; the next name has been selected for the 

 species). 



Pholidops ? linguloides and P. ? lamellosa Hall, ibidem, p. 414, pi. iii, fig. 11 

 (the latter name is a lapsus for P. linguloides) . 



Pholidops linguloides and P. oblata Hall and Clarke, 1892, Nat. Hist. N. Y., 

 Pal., vol. viii, pt. i, p. 157, pi. xli, flgs. .35, 36. 



Occurrence. — Hamilton, Aurora, and Canandaigua Lake, New York. 



' Verb. d. k. russischen min. Gesell. St. Petersb., sec. ser., vol. xxxvi, 1899, 

 pp. 331-337. 



