REVISION OF PALEOZOIC STELLEROIDEA. 149 



"Marginal [inframarginal] plates well developed and conspicuous, 

 and but slightly smaller than the adambulacrals. Both supra- and 

 inframarginals appear to be present. 



"The abactinal [actinal] furrows are large and subpetaloid. They 

 are bounded by large tuberculate adambulacral plates. The ambu- 

 lacral plates are boot-shaped [and slightly alternating]. The pores 

 for the podia are large, and occur on the suture between the adam- 

 bulacrals and ambulacrals. 



"The adambulacral elements in the oral armatiu*e are prominent, 

 and consist of five pairs of subtriangular plates. 



" Tj'pe-species : Asterias antiqua, Hismger 1837. Silurian: Got- 

 land. ' ' No other species of this genus is known. 



Remarlcs. — Of this genus only the actinal side is known and the 

 published figure from a drawing by Mr. George Lilejevall is one of 

 the best of Paleozoic starfishes. Lindstromaster differs from Petras- 

 ter in but one generic character, if it be a generic one, m that the 

 ambulacral fmTows are large and subpetaloid m the former and 

 narrow and slowly tapering in Petraster. However, since the abac- 

 tmal area is unknown in Lindstrdmaster there probably will be dis- 

 covered in this area differences distinguishing it from Petjuster. It 

 is also probable that the marginals m Lindstromaster which Gregory 

 thinks are "both supra- and inframarginals" tying dhectly super- 

 posed arc only inframarginals. In Siluric starfishes these plates 

 have not attamed the superposed position so marked in recent genera. 

 The supramarginals are here never true marginals and always he 

 more or less inside the inframargmals, which are the true marginals of 

 these early genera. For other remarks see Palseostella. 



The name Hisingeraster was pubhshed after Gregory's name and 

 is based on the same genotype. 



When more material is obtained and the genus is restudied, com- 

 parisons should also be made with Palasterina j^rimseva, as the two 

 forms appear to have nmch in common. 



LINDSTROMASTER ANTIQUUS (Hlsinger). 



Asterias antiquaKisiNGER, Lothaca Suecia, 1837, p. 89, pi. 26, fig. 6. 

 Lindstromaster antiqua Gregory, Geol. Mag., dec. 4, vol. 6, 1899, pp. 343, 347, 



pi. 36, figs, la, 16 (complete synonymy given here). — Schondouf, Jahrb. 



nassauisch. Ver. Naturk., Wiesbaden, vol. 63, 1910, p. 225. 



A single specimen is known from "Bed C," Mount Hoburg, Got- 

 land, coirespondhig to the Wenlock of England. It is in the Angelin 

 collection of the Mineralogical Museum at Copenhagen. 



