200 BULLETIN 88, UNITED STATES NATIONAL MUSEUM. 



Genus PALASTERISCUS Sturtz. 



Palasteriscus Sturtz, Palseontograpliica, vol. 32, 1886, p. 95, pi. 14, fig. 1; vol. 36, 

 1890, p. 223, pi. 28, figs. 23-236; pi. 29, fig. 24; Verh. naturh. Ver. preuss. 

 Rheinl., etc., vol. 50, 1893, pp. 44, 61. 



This genus differs from Loriolaster in being more decidedly stellate, 

 with longer and more slender rays and less extensive interbrachial 

 arcs. The abactinal and interbrachial areas are made up of innumer- 

 able, small, variously shaped, loosely interlocking, stellate plates. 

 These areas in Loriolaster appear to be smooth. 



Madreporite very large, actinal. 



The genoliolotype, P. devonicus (same citations as above), is the 

 only species and is very rare in the Lower Devonic roofing slates of 

 Bundenbach, Germany. 



Cat. No. 59389, U.S.N.M. 



Genus ECHINASTERELLA Sturtz. 



Echinasterella Sturtz, Palseontograpliica, vol. 36, 1890, p. 225, pi. 28, figs. 26, 26a, 

 27; Verb., naturh. Ver. preuss. Rheinl., etc., vol. 50, 1893, pp. 53, 73. 



This form seems to be closely related to Palasteriscus, and without 

 material for examination it is difficult to point out the differences 

 supposed to be generic. Sturtz describes the ambulacrals as oppo- 

 site, but his figures 26 and 27 show that they are slightly alternating. 



The genoTiolotype, of which three imperfect examples are known, 

 is E. sladeni (same citations as above). It is from the Lower Devonic 

 of Bundenbach, Germany. Another form which probably belongs 

 here is E. ( ?) darwini Clarke, from the Devonic of Brazil. 



ECHINASTERELLA (?) DARWINI Clarke. 



Echinasterella ? darwini Clarke, Monog., I, Serv. Geol. Min. Brasil, 1913, p. 315, 

 pi. 27, figs. 9-12; Bull. N. Y. State Mus., No. 164, pi. 34, figs. 1-3. 



Original description.^' Oi this fine starfish the collections con- 

 tain two specimens, one, that from which our illustrations are taken, 

 a sharp cast of an oral surface with the arms extended, in a shale 

 sufficiently compact to permit a squeeze to be made of the entire ex- 

 posure. The other is a considerably distorted individual also chiefly 

 with oral exposure. I have placed the species only provisionally with 

 Stiirtz's genus Echinasterella, which was described from the Bunden- 

 bach slates, feeling that in all probability both this species and its 

 associated Aspidosoma? pontis will be found on close analysis by 

 expert students of the Asteroidea to pertain to other genera. The 

 structural features presented by E.f darwini are as follows: The 

 oral surfaces of the arms are very broad, the ambulacral grooves 

 narrow, and the plates arranged opposite each other. The ambulacral 

 plates are turned obliquely inward and are broadened at their inner 

 ends. As preserved these show only their upper edges except where 



