TEANSLATIONS AND NOTICES 



OF 



GEOLOGICAL MEMOIRS. 



Oil XrLLiroRA AXNXJLATA. By Professor A. E. Reuss, For. Corr. G.S. 



[Proceed. Imp. Geol. Inst. Vienna, December 18, 1866.] 



Although very common in the Upper Trias and in the Muschel- 

 kalk, and even in places constituting whole beds by itself, the affi- 

 nities of this fossil are still doubtful, partly on account of its rare 

 occurrence in an entire and well-preserved condition. Some 

 varieties have been taken for segments of the stems of Crinoids. 

 Its discoverer, Prof. Schafhautl hinted at its resemblance to 

 Ceriopora, but nevertheless ranked it among the Bryozoan genus 

 Nullipora. He subsequently made it the type of his new genus 

 Diplo])ora, and divided it into a number of species, which are no 

 more than different conditions of the same form. Prof. Giimbel 

 made it a species of the Anthozoan genus GliceUtes ; Stoppani de- 

 scribed it as Oastrochoina ohtusa ; and Dr. Eck, without deciding 

 about its nature, gave it the name of Cylindrum a7inulatum. A 

 close examination of a number of specimens from different localities 

 threw no light on its intimate structure, or on its true nature. 

 Cylindrum annidatum is certainly closely related to the Bryozoa, 

 with which, however, it has nothing more in common, in regard to 

 its internal structure, than Nidlipora, Chcetetes, or Gastrochcena. 

 In fact its interior is hollow, and but accidentally filled up with 

 calcareous matrix (see Schafhautl, Lethaea, pi. Ixv. e. fig. 18), and 

 not filled up with cellular substance as Schafhautl supposed when he 

 stated it to be analogous to Ceriopora and Cricopora. The cellular 

 cavities in the interior of the septa have no direct mutual com- 

 munication ; they are disposed in circular ranges ; their orifices 

 (Dr. Carpenter's "junctural interspaces") open into the central 

 cavity of the stem, and the channels into these inner orifices ; these 

 channels are disposed in alternating double ranges, and end out- 

 wardly in the pores of the surface. All these characters denote an 

 affinity with the complicated forms of Dactylopora (see Dr. Car- 

 penter's ' Introduction to the Study of the Eoraminifera,' pi. x. 

 figs. 17, 18, Dactylopora reticulata, and figs. 24, 29, D. cylindracea). 

 Prof. Schafhautl's distinct species are merely more or less well- 

 preserved specimens of Dactylopora annidata ; while Gastrochcena 

 ohtusa, Stopp., and Cylindrum annulatum, Eck, may perhaps, after 

 closer examination, prove to be distinct species of the same genus. 



[Count M.] 

 vol. xxih.— part ii. e 



