496 



PROCEEDINGS OF THE NATIONAL MVISEVM. 



roL.53. 



ENCOPB MEGATREMA, new species. 



Plate 68, fig. 1. 



This spocios is roprosontod by ono fairly good tost with its counter- 

 part, and in addition somo 12 fragments which yield helpful facts 

 on closo study. From the incompleteness, measurements and some 

 details will have to bo given in general terms or omitted. As a whole, 



-J . ^ 



Fro. 3.— Encope meo\tbbha Holottpe, natural size. The area snowiNa part oy ahbvla- 



CRUM 11 IS DRAWH FROM A FRAGMENT. RESTORATIONS INDICATED BT DOTTED LINES. 



Fio. 4.— Section op lunule to suow inclined faces, drawn from two fragments. 



the tost is low, elongated, thin on the borders and with shallow 

 ambulacral notches and an enormous lunule in interambulacrum 5. 



From the best specimen, which is figured, the length probably was 

 about 120 mm. and the width about 106 mm.; thickness of the test 

 at its center is 10 mm. Ambulacral notches are shallow and quite 



