210 BULLETIN 88, UNITED STATES NATIONAL MUSEUM. 



of the madreporite and the absence of interbrachial inframarginals. 

 It is clearly a Palseosolaster. 



PAL^JOSOLASTER (?) GYALUM (Clarke). 



Plate 34, fig. 1. 



Helianthaster gyalum CLARKE, Bull. N. Y. State Mus., No. 121, 1908, p. 63, pis. 

 12, 13. 



Original description. The New York specimens, i i Helianthaster 

 gyalum nov. are smaller than H. rhenanus. The arms are more 

 numerous and appear to be quite uniformly 24-25. Compared to 

 H. rhenanus they are relatively short, but very long compared with 

 the size of the disk, which is much suppressed, and on none of the 

 specimens, all showing the oral surface, is any distinct evidence of 

 it visible, so deeply do the arms cut into it and so closely do they 

 lie together. Notwithstanding this apparent retreat of the disk the 

 madreporiform plate is very large. This organ is preserved in but one 

 example, but here it overlaps two adjoining interbrachial angles and 

 the mouth parts pertaining thereto. Instead of being a flat or 

 concave elongate plate, as in H. rhenanus, it is highly convex and 

 circular; its surface markings less distinct and coarse in that species. 



"The great oral aperture is margined by a series of pronounced 

 ' jaws' or sharp projecting elevated angles the sides of which take 

 origin from the margins of adjoining arms. These oral projections 

 are slightly expanded at their tips into blunt points comparable to 

 but smaller than the 'Hocker' of H. rhenanus, but like them carry 

 small spines projecting inward. The solidity and strength of these 

 mouth parts is indicated by their prominence and elevation as shown 

 in figure. * * * The reentrant angle at the base of each arm is 

 narrow, long, and acute, much more extreme in these respects than 

 in H. rhenanus and very much more elevated." 



Actinally the rays have two columns of plates of which the ambu- 

 lacrals are by far the most prominent, are opposite one another or 

 slightly alternate, and occupy the comparatively wide ambulacral 

 furrows. The adambulacrals are narrow columns and apparently as 

 many in number as the ambulacrals. Laterally each adambu- 

 lacral bears several spines. 



Locality and formation. A slab with three individuals from the 

 Portage (Upper Devonic) at EaiTs quarry, Ithaca, New York, is now 

 in Cornell University. 



Remarks. The writer has not seen these specimens, but the illus- 

 trations seem to indicate that the " pronounced jaws" are made up 

 of small ossicles of which there are at least five in each column. 

 Further, that these ossicles are more probably the continuation of 

 the narrow adambulacrals than of the ambulacral columns into the 

 great oral area, and that proximally to these lie the minute pairs of 

 oral armature pieces. 



