2 20 NEW YORK STATE MUSEUM 



and introduced for them the term Chaenocardiola. Beushausen ' has 



employed the latter name and has introduced an additional generic division, 



Prochasma, represented by Miinster's L. pyrif orme. 



The first of Miinster's species described is L. semistriatum. one 



of the Chaenocardiola group. To this species we should legitimately have 



recourse in establishing the value of the genus. It is a matter of serious 



regret that no one has taken up for reconsideration the important work of 



Miinster on these upper Devonic lamellibranchs. The description of the 



Lunulicardiidae of the Rhenish Devonic given by Beushausen is a most 



valuable account of these shells but does not specially concern itself with 



Miinster's species. Lunulicardium semistriatum was described 



as follows : 



Wider than long ; opposite the large and 

 crescentic incurvature on the anterior side is a 

 low incision which in the lithograph is made 

 too deep ; the lower margin has a subsemicir- 

 cular groove, the lower half of the surface is 

 covered with radiating striae, the umbonal sur- 

 Fig. i Luniiiicardium semistriatum cafter face highly convex with a few concentric 

 MUnster > grooves ; the abruptly arched and acute beak 



anterior to the great lunule. 



It appears from this description and is furthermore evident in the 



descriptions of other species of the same group that Miinster regarded the 



characteristic lateral marginal flattening of the valves as a lunule. In Holz- 



apfel's earlier observations the author described a number of Lunulicardia 



from the lower Upper Devonic of Westphalia and in a later work briefly 



discussed Miinster's species, indicating the probability of there being 



therein distinct groups. Here it was that he proposed to eliminate under 



the term Chaenocardiola, shells having a long lunule and byssal cleft cutting 



the valves from beak to basal margin almost midway, and having opisthogyre 



beaks. The species taken as the type of this genus, however, is C. h al i o- 



t o i d c a Roemer (sp.) from the Culm. 



'Die Lamellibranchiaten des rheinischen Devon init Ausschluss der Aviculiden: 

 Abhandl. d. Kdnigl. preuss. geol. Landesanstalt. N. F. 1895. heft 17. 



