No. 2314. 



UBT OF RECENT BRACIJIOPODA—DALL. 



291 



The crural plates are narrow and deeply excavated, the crura rather 

 long, slightly twisted and concave on their inner faces. The space 

 behind the dental props is very small and solidly filled with cement in 

 the older specimens. The valves are unusually thick, solid and cal- 

 careous. Until I got more perfect specimens than the original types, 

 I suspected that the //. columns of Hedley, might be identical, but 

 with the receipt of perfect individuals an inspection showed suffi- 

 cient distinctions in and about the cardinalia. 



The pedicel tube, homologous with the "collar" of Jackson, but 

 greatly produced and developed, would certainly be taken as of gen- 

 eric value in a fossil species and is not distantly related to the arrange- 

 ment in the Devonian Pseudosyrinx. 



BASILIOLA POMPHOLYX, new species. 



Shell pellucid, much inflated, light gray, polished, without radial 

 striation and only very faint incremental lines ; pedicel valve with a 

 wide concave mesial fold which is not laterally well defined except 

 at the margin where the valve projects in a squarish fashion; the beak 

 is low, the foramen small, under the apex; the del ti dial plates wide, 

 firmly united in front of the foramen and produced in a sort of gutter 

 in front; when not worn off the extremity of this gutter extends be- 

 yond the plane of the incurved beak; internally the lower extensions 

 of the plates unite without any visible suture to form a broad tube 

 of which the anterior edge is free from the dome of the valve and ex- 

 tends forward as far as the beginning of the dental props; the hinge 

 teeth are very small and weak but strongly cross-striated; a narrow 

 groove extends from under the tube mesially as far as the rather 

 small muscular impressions, the dental props are thin and incon- 

 spicuous; the brachial valve is almost hemispherical in inflation, 

 with a broad squarish anterior fold; the crural plates wide, short, 

 separated clear to the apex, the crura very small, short, guttered 

 below; the cavity of the beak sometimes with a low thread-like 

 septum extending forward to the muscular scars, sometimes with a 

 shallow groove wliich after separating the muscular impressions 

 bifurcates widely, extending nearly to the anterior margin. Height 

 of shell 26; width 28; maximum diameter 17 mm. 



