'72 BULLETIN 88, UNITED STATES NATIONAL MUSEUM, 



once in having five instead of four columns of large abactinal plates. 

 There are also a far less number of the accessory plates so numerous 

 on the disk and the proximal medial areas of the rays in Palseaster 

 niagarensis. 



Hall ^ refers a fragment to this species which clearly is of quite 

 another species. It is very far removed from P, niagarensis and 

 for the present need not be considered. The specimen has not been 

 seen by the writer, 



AUSTRALASTER, new genus. 

 Plate 4, fig. 4. 



Palseaster (Mjnosfer) Etheridge, jr. (part), Mem. Geol. Surv. New South Wales, 



Pal., No. 5, pt. 2, 1892, p. 74. 

 Monaster Gregory, Geol. Mag., dec. 4, vol. 6, 1899, p. 345 (not of Etheridge, jr.), 

 Australaster Schuchert, Fossilium Catalogue, Animalia, pt. 3, April, 1914, p. 12. 



.AusiraZ=southern and aster. A Paleozoic starfish restricted to 

 Australia. 



Generic diagnosis. — Animal attaining a very large size, with five 

 long, slender, ahnost straight-sided rays, terminating bluntly. 

 Interbrachial areas comparatively small, widely concave, and occu- 

 pied by ponderous, single, axillary marginals and inframarginal 

 plates. 



Abactinal area unknown (see A. {?) stutchhurii) . 



Actmally the animal is bounded by inframarginal plates which 

 however do not appear to be present in the distal third of the rays. 

 If such plates are present in these outer regions, they are cither 

 very small or gradually pass from the actmal to tlie abactinal area, 

 the latter condition occmTuig in related genera. The infraraarginals 

 in the outer third of the rays are small, sub quadrangular, and rounded, 

 thence they increase rapidly in size proximaUy, become decidedly 

 transverse, and in the axils the columns abut against a very large 

 axillary inframarginal. The largest plate is the axillary marginal, orad 

 to which occur the pairs of enlarged oral armature ossicles, Tha 

 inframarginals appear to be nearly smooth and devoid of spines. 



The adambulacrals in the distal third of the rays are numerous, 

 very short, but quite wide — that is, are decidedly transverse, and 

 decrease rather rapidly in breadth toward the tips of the rays. 

 ProximaUy these plates also decrease quickly in width and rapidly 

 pass inside of the inframarginals. Inside of the axiUary marginals 

 the plates are again promment and especially the pairs of orail arma- 

 ture pieces. Each adambulacral plate bears prominent tubercles 

 for the articulation of stout but short spines. The columns have 

 the pieces arranged with a decided slant outward and distally. 



1 Palseontology of New York, vol. 2, 1852, p. 332 and pi. 85, figs. 8-10. 



