PALEONTOLOGIC CONTRIBUTIONS 63 



or under arm plates, it has in common with Miospondylus (repre- 

 sented by Ophiura rhenana 1 Stiirtz) . Sollas and Sollas 2 

 who have restudied the type and only known specimen of that 

 species state that these underarm plates are seen only in one arm 

 which has undergone rotation and that " near the disc where the 

 rotation undergone is less, the underarm plates are clearly paired." 

 They consider, therefore, their real nature as problematic. From 

 the identity in shape between the underarm plates of Miospondylus 

 as figured by Stiirtz and those of our species, we believe that these 

 structures are really present in Miospondylus as figured by Stiirtz. 

 It is stated by Sollas and Sollas regarding Miospondylus 

 rhenanus, that "curious jointed structures, looking like 

 jointed and flattened spines, are present on the lateral aspect of the 

 arms and are named by Stiirtz side shields." We consider it prob- 

 able from this statement and Stiirtz's figure 2, that Miospondylus 

 had similar wedge-shaped lateral spines as our genus. As in 

 Klasmura, so also in Miospondylus most 

 parts were originally covered by a heavily 

 armed integment. The differences between 

 Miospondylus and Klasmura, undoubtedly 

 closely related genera, consist in the presence 

 of jawplates, reported as absent in Mio- 

 spondylus by Gregory, and of the spoonlike 

 structures in the interangles of the oral 

 frames in our genus. Also the absence of 



dorsal plates, recorded by Stiirtz, though still „. ,- , 



^ J ° Pig. 29 Klasmura 



doubtful on account of the unfavorable mirabilis nov Di- 



preservation of the dorsal side, and the agrammatic view t of 



presence of " dorsal plates " (or projecting right half of portion of 



parts of the vertebral ossicles) in Klasmura actinal side of ray, 



,■„ r -r , ■ showing ventral plates 



may constitute a difference, for, it present in . 



Miospondylus and forming a median promi- 

 nent ridge, they would probably have become apparent on one of 

 the rays. No traces of a relatively large disk, such as is figured of 

 Miospondylus, have as yet been observed in Klasmura, but it is 

 possible that this failed of preservation. We believe, that the lateral 

 series of long wedge-shaped, hollow spines with their saddle-shaped 

 interlocking bases will, in time, be found to constitute a character 

 distinguishing Klasmura from the other genera of the Eoluidiidae ; 



1 See Verhandl. naturh. Vereins der preuss. Rheinlande, v. 50, p. 29, pi. 1, 

 figs. 1-3. 1893. 



2 Philosophical Trans. Roy. Soc. of London, ser. B, v. 202, p.. 226. 1911-12. 



