﻿104 BULLETIN 103, UNITED STATES NATIONAL MUSEUM. 



Encope megatrema Jackson. Miocene/ Gatun formation, station 

 6030, about one and one-half miles from Camp Cotton, toward 

 Monte Lirio. 



Echinolampas semiorhis Guppy. Upper Oligocene, Emperador lime- 

 stone, Gaillard Cut, stations 58666 and 6019p'. 



Schizaster artniger W. B. Clark. Miocene ( ? ) ,^ Bonilla, Costa Rica. 



Schizaster cristatus Jackson. Miocene (?),^ Brazil, Costa Rica, sta- 

 tion 5505. 



Schizaster panamensis Jackson. Miocene,^ Gatun formation, near 

 Gatun, at stations 6008 and 7294. 



DESCRIPTION OF SPECIES. 



CLYPEASTER LANCEOLATUS Cotteau. 



Plate 46, figs. 1, 2. 



Clypeaster lanceolatus, Cotteau, Descripcion de los Equinoides Fossiles de la 

 Isla de Cuba, Bol. Com. del. Mapa Geologico de Espaua, vol. 22, 1897, p. 

 39, pi. 9, figs. 1, 2, 3.— Jackson, Proc. U. S. Nat. Mus., vol. 53, 1917, p. 

 490, pi. 62, figs. 1, 2. 



This species is one of the few in the series from the Panama Canal 

 Zone that seems referable to an already published species. There 

 are seven specimens, all in good condition of preservation and repre- 

 senting two localities which, however, from the character of the 

 material may be nearly associated. I give measurements of the 

 largest specimen of the set. Length, 95 mm. ; width, 77mm. ; height, 

 21 mm. Test elongate, wider behind than in front, moderately ele- 

 vated, deeply concave in ventral view. Ambulacral petals elevated, 

 distally acuminate, nearlj^ closed and pinched up as if squeezed 

 between the thumb and finger. Anterior petal III equal in length 

 to petals I and V and a few millimeters longer than are the anterior 

 pair II and IV. The anterior petal III is more widely separated from 

 petals II and IV than are those latter from I and V. Interporiferous 

 areas of petals are elevated, wide, being about equal to both porif- 

 erous areas. Interambulacra are narrow, extremely so near the 

 apical disk. Tubercles are small and of about the same size dorsally 

 and ventrally. Apical disk is central, mouth central, deeply sunken, 

 periproct ventral, about four mm. from the posterior border of the 

 test. The original material described by Cotteau is from the " Mio- 

 cene " of Matanzas, Cuba, where he says it is very rare. It is appar- 

 ently more or less common in the Canal Zone, as there are seven speci- 

 mens from that region. 



^ This formation is more appropriately referable to the lower Miocene, i. e., Burdigalian, 

 than to the Upper Oligocene. — T. W. V. 



