Ill 



TWO NEW STARFISHES FROM THE SILURIAN OF 



ARGENTINA 



In this paper two new species of starfishes from the Silurian 

 of the Cerro Blanco are described, which were sent by Prof. W. 

 Bodenbender to Doctor Clarke. They are labeled as coming from 

 the Devonian of Jachal (Cerro Blanco) =Quebrada del Aguad- 

 ida. Prof. E. Kayser in this paper : Beitrage zur Kenntniss einiger 

 palaozoischer Taunen Siid-Amerikas, 1 mentions already the occur- 

 rence of starfishes at the Cerro Blanco. He states : "At the Cerro 

 Blanco (between the jachal valley and Iglesia) there are still two 

 more, higher fossil horizons, the lower of which is marked by abund- 

 ant remains of Lingula subalveata and P h o 1 a d e 1 1 a 

 r a d i a t a , the upper by numerous conularias, starfishes, crinoids, 

 Spirophytons, etc." The beds which carry these starfishes are 

 called the " Conularia sandstones " ; they occur only on the west 

 side of the Jachal valley, and are supposed to be of about the 

 same age as the beds with Vitulina, etc. on the east side of the 

 same valley (namely, Middle Devonian, see op. cit. p. 310). Doctor 

 Clarke 2 from a close analysis of the species of the Argentina 

 Devonian, has later arrived at the conclusion that there are two 

 distinct groups of fossils, the first of which distinctively represents 

 the Devonian of the Falkland islands and of Ponta Grossa, while 

 the second, to which the starfishes belong, constitutes (1) an 

 assemblage " not known elsewhere in any admitted Devonian fauna, 

 either of the northern or southern hemisphere," and (2) " embraces 

 a series of well-defined Silurian (Upper Silurian) type forms, 

 variant to a noteworthy degree in species but not widely in generic 

 expressions." In the final tabular lists (op. cit. p. 351) the fossils 

 of Argentina are arranged by localities and by their print indicated 

 as either of Silurian or Devonian age. The fossils of the Cerro 

 Blanco are about half Silurian and half Devonian; as Silurian 

 elements being cited : asteroid (Kayser) , Orthothetes small, 

 cf . "arctostriata" (Kayser) , Clintonella boden- 

 benderi, Brachyprion fascifer, Australina 



1 Zeitschrift der deutschen geol. Gesellsch. 49, p. 276. 1897. 



2 Monographias do Servigo geologico e mineralogico do Brasil, v. t, 1913, 



R- 54, 334, 351.. 



116 



