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 1 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 hus not been 

 seen by the writer. 



AUSTRALASTER, new genus. 

 Plate 4, fig. 4. 



Palseaster ( Monaster) 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, Fossiliiim Catalogus, Animalia, pt. 3, April, 1914, p. 12. 



Austral=sout1n.eTn and aster. A Paleozoic starfish restricted to 

 Australia. 



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

 long; slender, almost 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. (?) stutcfiburii) . 



Actinally 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 either 

 very small or gradually pass from the actinal to the abactinal area, 

 the latter condition occurring ha related genera. The inframarginals 

 in the outer third of the rays are small, subquadrangular, and rounded, 

 thence they increase rapidly in size proximally, become decidedly 

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

 axillary inf ramarginal. The largest plate is the axillary marginal, orad 

 to which occur the pairs of enlarged oral armature ossicles. The 

 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 hi breadth toward the tips of the rays. 

 Proximally these plates also decrease quickly in width and rapidly 

 pass inside of the inframarginals. Inside of the axillary marginals 

 the plates are again prominent and especially the pairs of oral 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. 



i Palaeontology of New York, vol. 2, 1852, p. 352 and pi. 85, figs. 8-10. 



