674 PROF. J. W. GREGORY ON [NOV. 191 I, 



ScHIZASTER EDERI, 1 sp. IIOV. (PL XLYII, figs. 4 «-4 C.) 



Diagnosis. — Test : cordate ; the breadth is equal to or slightly 

 greater than the length. The greatest breadth is about half-way 

 along the length of the test. The test is high, and raised behind to 

 a prominent keel. The summit is very excentric posteriorly at 

 onry a fifth of the length from the posterior end. The apical 

 disc is a little behind the centre. There is a long gradual slope 

 forward from the summit nearly to the anterior edge, where the 

 ambitus is steep and well rounded. 



Petals : deeply sunk. 



The anterior ambulacral furrow is long, and has long steep 

 parallel sides, as also small numerous pores. The pores in each pair 

 are bigeminate, and on the apical side of the plate is a conspicuous 

 granule immediately above the pore-pairs (fig. 6). The plates in 



The granulation of the antetior ambulacral plates in a § b. 



.<*£> 



m 



O oo 



,3. i a ° o o ra*Q. 



7 



O } / O o o o 



a h 



a = Sch. rimosus, after Cotteau. ' Pal. FraiHj. : Ech. Eoc.' pi. c, fig. 5. 

 b = Schizaster ederi, sp. nov. 



the anterior ambulacral furrows have numerous crowded granules 

 arranged in two rows along each plate, with about four granules in 

 each row. 



Antero-lateral petals long and but slightly sinuous, with thirty 

 pairs of pores on each side. Postero-lateral petals short and deep, 

 and curved backwards beside the keel : they have twenty-two pairs 

 of pores on each side, of which the seven pairs nearest the apical 

 disc are much smaller than the others ; the difference in size is 

 abrupt. 



Periproct large and oval, pointed above and below, raised high on 

 the posterior wall, and beneath a slightly overhanging projection 

 from the keel. Peristome near the anterior edge. 



Dimensions : — 



Sch. desori. 



Sch. rimosus Wright's Wright's 



Sch. ederi. (Cotteau). text. fig. 



mm. mm. inches. mm. 



Length 48 59 2-8 54 



Breadth 49 55 27 50 



Height 32£ 33 P8 (35?) 



Length of antero-lateral petal 16 21 13 16 



Length of postero-lateral petal 10 10 0*75 11 



Named after Dr. M. D. Eder, the doctor of the Expedition. 



