INCERTAE SEDIS. 



256 



'Xenocidaris clavigera Schultze. 

 Text-figs. 256a-25Gd, p. 455. 



Xenocidaris clavigera Schultze, 1866, p. 126, Plate 13, figs. 3a-3h; Love'n, 1874, p. 44; Jackson, 1896, p. 222; 



Klem, 1904, p. 75; Lambert and Thie"ry, 1910, p. 126. 

 Pdaeocidaris rhenanus Quenstedt, 1875, p. 377, Plate 75, figs. 30-37 (figs. 30-32 are doubtful). 1 



Spines are slender proximally, from this portion enlarging by a gradual tapering, or toward 

 the distal end rapidly expanding into a trumpet-shaped form. Distally, the border and 

 inflated terminal face are set with fluted or spinulose ex- 



M 



pansions directed distally. These spines are quite unlike 

 anything else known in the Palaeozoic Echini, but recall 

 some of the peculiar cidarid spines occurring in the Meso- 

 zoic. They can well be compared to such spines as those 

 of the Jurassic Tiaris conoideus suevicus (Quenstedt, 

 1875, Plate 70, figs. 25-28) to which Quenstedt (1875, p. 

 377) compares them. Eleven specimens in the British 

 Museum measure up to 31 mm. in length, and at the 

 distal expanded tip measure up to 6 mm. in diameter. 



The spines described by Quenstedt as Palaeocidaris 

 rhenanus are from Eifel specimens, and his figures 33 to 

 37 are certainly the same species as Schultze's Xenocidaris 

 clavigera. His figures 30 to 32 are doubtful, but are 

 apparently closely allied as they have a similar club 

 shape, but are not distally truncated with terminal spin- 

 ules in a crown like the spines of clavigera. 



Middle Devonian, Gerolstein, Prussia, Museum of Comparative Zoology Collection 3,044, 

 some thirty spines, including the cotypes from the Schultze Collection; same locality, British 

 Museum Collection E 1,269, E 398; Munich Museum; Strassburg Museum; Freiburg i. B. 

 Mus3um; Kerpen, Prussia, Schultze Collection, Museum of Comparative Zoology 3,059. 



Xenocidaris conifera SchliSter. 

 Xenocidaris conifera Schluter, 1881, p. 213; Klem, 1904, p. 76; Lambert and Thie"ry, 1910, p. 126. 



Spines smooth and conical. 



Middle Devonian, Hillesheimer-Mulde, between Kerpen and Mollenbach, Germany. 

 Professor Steinmann informs me that Schluter's original specimen or specimens are in the 

 collections at the museum in Bonn. 



1 See footnotes, p. 288. 



255 



TEXT-FIO. 255. Xenocidaris cylindrica 

 Schultze. Middle Devonian, Gcrolstein, 

 Eifel, Prussia. Cotype, enlarged. After 

 Selmltze, 1866, Plate 13, fig. 4b. Museum 

 of Comparative Zoology Coll., 3,201. 



TKXT-FIO. 256a-d. Xenocidaris clavigera 

 Schultze. Middle Devonian, Muhlcnberg, 

 near Gerolstein, Eifel, Prussia. Cotypes, en- 

 larged. After Schultze, 1866, Plate 13, figs. 

 3, 3a, 3c, 3d. Museum of Comparative 

 Zoology Coll., 3,044. 



