198 Systematic Paleontology — Middle Devonian 



from six to eiyliteen low, roimdod, often obscure plications; concentric 

 inibricatino- ami lamcllosc striae, which are sometimes distant and fre- 

 quently crowded; the concentric striae studded ■with elongated spines or 

 tubercles, which are arranged in parallel bands and ma}' be regarded as 

 interrupted radiating striae. 



But few specimens of this .species have been found in Maryland and 

 only a single imperfectly jDreserved ventral vahe was available for com- 

 parison in compiling the above description. The small number of low, 

 rounded plications, conspicuous concentric striae and concentric rows of 

 tubercles, however, readily distinguish the species from any other found 

 in the ]\Iid(lle Devonian of Maryland. 



Concerning the specimens occui-ring in the Onondaga member, Kindle 

 says: "The collection contains three small spccmiens of a Reticularia 

 haAing a breadth along the hinge-line of about 5 mm. and with 3 to 4 

 plications on each side of the fold and sinus. These i>robably represent 

 eitlier immature ijidividuals or a dwarfed form of E. pinhriata." 



Length, 15-'25 mm.; width, 20-35 mm. 



Occurrence. — Bomxey Formation, Onondaga Member. Williams 

 Road, 314 miles southeast of Cumberland. Hamilton Member. East 

 bank Evitts Creek below Wolfe Mill. 



Collections. — Maryland Geological Survey; Xew York State [Museum; 

 American IMuseum of Xatural History. 



Spikieer cf. coNSOBRiNus (d'Orbiguy) 

 Plate XIX, Fig. 13 



Delthyris ziczac Hall ( non Roemer). 1843, Geol. N. Y., pt. iv, pp. 200, 201, 



fig. 5. 

 Spirifera consohrina d'Orbigny, 1850, Prodrome Pal., i, p. 98. 

 Spirifara ziczac Hall, 1807, Pal. N. Y., vol. iv, p. 222, pi. xxxv, figs. 15-23. 

 Spirifer consobrhui.s Hall and Clarke, 1893, PaL N. Y., vol. viii, pt. ii, pp. IG, 



30, pi. xxxiv, figs. 9, 18; pi. xxxvli, figs. 9. 10. 

 Delthyris consobrina Schuchert, 1897, Bull. U. S. Geol. Surv., No. 87, p. 20G. 

 Spirifer (Delthyris) consobrinus Gralmu and Shimer, 1909, N. Am. Index 



Fossils, vol. i, p. 331, figs. 422a, b. 



Description. — Shell medium size, gibbous, semielliptical in outline, 

 with the hinge-line equaling or greater than the width of the shell below; 



