630 Systematic Paleoxtoi.ogy — UrPER Devoniax 



Family LUNULICARDIIDAE 



Genus LUNULICARDIUM Munster 



There has been a recent effort to restrict the application of this term 

 ver)' narrowly and this has given opportunity for the erection of a con- 

 siderable number of additional generic terms for shells commonly passing 

 as LitnuHcardium. The authors after a careful analysis of an extensive 

 series of these shells have failed to find a satisfactory basis for either the 

 restriction of the genus or the renaming of its species. Lunulicardium has 

 subtriangular shells with a long and arched hiatus between the valves on 

 the posterior slope. This opening is bounded by narrow smooth areas 

 (sicse) which may be either erect or projacent and which start at the umbo 

 from the outer margin of the pi'imitive shell. Behind the beaks is a short 

 triangular cardinal area. The surface may be radially plicated, striated 

 or smooth. 



These shells are very abundant in the Naples fauna of New York 

 especially in the Naples subprovince. In ^Maryland only the following two 

 small species have been observed. 



Lunulicardium encrixitum Clarke 

 Plate LXII, Figs. 1-3 



Lunulicardium encrinitum Clarke, 1904, N. Y. State Mus., Mem. vi, p. 239, 

 pi. il.fig. 20. 



Description. — Shell small subtriangular, umbo acute, lateral margins 

 diverging rapidly and anterior margin forming a broad curve, not greatly 

 truncating the anterior moiety of the commissure, its length equalling 

 about two- thirds of the length of the shell. Sica? smooth and nearly erect. 

 Body of the shell generally convex, and covered with ver}' fine simple 

 radial striae which nmuber 100-125. Extremely fine concentric strise are 

 observable with favorable preservation. 



Length 7 mm.; height 7 mm. 



This species in New York has been recorded only from the village of 

 Naples and it is on the specimens from this locality that the species is 

 founded. 



