156 BULLETIN 88, UNITED STATES NATIONAL MUSEUM. 



Genoholotype and only species. — P. solida Stiirtz. Two speci- 

 mens are known from the Lower Devonic roofing slates, Bundenbach, 

 Germany. 



Remarks. — The starfishes from the Bundenbach roofing slates are 

 at best but poor fossils and were it not for the great skill of Mr. 

 Stiirtz in cleaning them out of the matrix their systematic position 

 could not well be determined. At best they are compressed to almost 

 paper thickness and distorted during solidification and shortening or 

 elongation of the slates. Under these circumstances it appears 

 best to redescribe the detailed abactinal characters as given by 

 Stiirtz. He mentions numerous paxillee and finds many characters 

 common to both Palseostella and the living Nectria. 



Palseostella is closely related to Palasterina, also to Lindstromaster, 

 and may be a descendant of the latter. The actinal structure in 

 Lindstromaster and PalxosteUa is nearly alike, both having large 

 inframarginals and adambulacrals, but the interbracliial areas in 

 the former are occupied by large closely adjoining plates, while in the 

 latter these are small and somewhat loosely interlocking. Abac- 

 tinally they can not be compared, since that side is unknown in 

 Lindstromaster. The greatest difference between Palasterina and 

 Palseostella is that the former has small inframarginals while in the 

 latter they are very large. Then the supramarginal and radial 

 columns in Palasterina are better developed and comparatively 

 larger, while in Palseostella they are shorter and most prominent in 

 the distal half of the rays. In the latter genus the central region 

 of the disk has no ring of fifteen basal radial and supramarginal 

 plates as in Palasterina. 



From this evidence it seems probable that the line of descent is 

 from Petraster to Lindstromaster to Palseostella in maintaining promi- 

 nent columns of inframarginals, while the line from Petraster to 

 Palasterina tends toward the reduction or elunination of these plates 

 as a conspicuous skeleton element. 



Palsenectria is based on the second specimen, and the genus is 

 described as follows: ''Should the described starfish [the second 

 specimen of Palxostella solida Stiirtz] prove not to be identical with 

 Palseostella, wliich is possible, even though not probable — the other 

 specimen is in the British Museum — I propose for it the new name 

 Palsenectria devonica." Unless the author takes the time to work 

 out his new forms, or decides the problem presented for himself, he 

 should not expect some one else to do this for him. Under these 

 circumstances the genus and species are regarded as not defined. 



Genus PSEUDOPALASTERINA Sturtz. 



Pseudopalasterina SturtZj Verb, naturb. Ver. preuss. Rheinl., etc., vol. 56, 1900, 

 pp. 219, 224. 



Genoholotype and only species. — Palasterina foUmanni Sturtz. 



