210 PEOr. P. M. DUNCAN S EEVISION OF THE 



Interradia with large plates, tlie plates beliind the peristome 

 forming a meridosternum. 



Peristome excentric in front, and its orifice witli a posterior lip 

 looking forwards, elliptical, transverse. Periproct in a depression 

 in the truncated posterior face, oval. A more or less complete 

 marginal fascicle passing below the periproct. 



Fossil. Lower Grreensand to White Chalk : England, Europe, 

 Asia, America. 



Such, forms of Gardiaster as G. fossarms, Benett, sj)., from the 

 Upper GrrecDsand, G. Gotteauana, d'Orb., besides a variety of 

 the first-named species, lead so decidedly up to InfulasterjU-dige- 

 now and Desor, that after due consideration I agree witli 

 Porbes in placing the species which were admitted by Hagenow, 

 d'Orbigny, and "Wriglit in that genus, with, one exception, in the 

 genus Gardiaster; or rather in a subgenus without a fascicle 

 {Infulaster). I have examined the types described by Forbes, 

 and they have no lateral or any kind of fascicle, and this was the 

 opinion of the late Dr. "Wright. All the characters of Gardiaster 

 are present in the species C. excentriciis, Forbes, and therefore 

 the absence of the fascicle is not of generic importance. I 

 do not consider that Gardiaster rostratus, Forbes (the Infu- 

 laster rostratus of Desor), belongs to the genus, and I admit it 

 in a new one, Sagenowia. 



Subgenus Infulastee, Hagenow (genus), 1851; Desor, 1858, ;S'y- 

 nopsis, p. 347. 



Test high in front, narrow ; anterior groove deep and with 

 strong lateral keels. Fascicle absent. 



Fossil. Upper Chalk : England and Europe. 



G-enus HAaEKOWiA, gen. nov. 



Syn. Gardiaster, Forbes (pars); Infulaster, Desor (Hagen.) 

 (pars) ; Stegaster, Pomel (pars) . 



Test small, long, narrow ovoid, low, with a long, slightly bent, 

 blunt-pointed rostrum, grooved beneath and arising from the 

 upper and anterior part of the test *. The narrow dorsum of 

 the test is saddle-shaped, short, and slopes from the rostrum to 

 the oblique posterior truncation, which is narrowly grooved from 

 below upwards. The anterior part of the test, beneath the 

 * See Forbes, 1852, Mem. Geol. Survey, Decade iv. pi. x. fig. 7. 



