354 PALEONTOLOGY OF NEW YORK. 



tered spines, of which thei^e is a well-defined row of six or seven on the car- 

 dinal margin. Thei-e are faint, irregularly concentric wrinkles among the 

 spine-bases. Apex of the brachial valve convex but the valve rapidly be- 

 comes concave, being of somewhat less curvature than the opposite valve. 

 Surface with conspicuous, irregular, concentric corrugations, and a few short 

 spines over the pallial region. 



Length of the original specimen, 9 mm. ; width along hinge-line, 10 mm. 



Upper Devonian. Rockford, Iowa. 



ERR^T^. 



Pag-e 57, line 12 fi-om bottom ; for " Plate I " read " Plate II." 



Page 75, line 6; for " jiosition " read "portion.'' 



Page 83, line 5; for "Leotobolus" read "Leptobolds." 



Page 99, line 23; for "and" i-ead "are." 



Page 99, line 24 ; insert " which " after " 25-29)." 



Page 108, under fig. 60 ; for " pedicle " read " brachial ; " for " brachial " read " pedicle." 



Page 139, line S fi-oin bottom ; Shabpe's specimens came from Cincinnati, Ohio, or vicinity, and were 

 probably examples of the form now known as T. millipunctata. Hall, as Emmons' T. tei-m'malis has not been 

 found in that locality. Sharps, however, mentioned Emmons' species as the type, and it may be best to 

 retain the New York form as such. 



Page 173, line 4 ; for " Lingula Unr/idiita" read •' Linrjula linguata." 



Page 18.'), line IS ; for " Strophodonta " read "Stropueodonta." 



Page 194, second pai-agi'aph. The deltidium of Orthis? Laureiithia is minutely perforate. 



Page 28S, line 15; dele "are." 



Page 303, line 2 ; for " XVa" read " XVb." 



Page 308, line 5 ; for " C. undidatus" read " C. undulal.a;" for "C Novascoticus " read C. Nuva- 

 scotUa." Corrected in part of the edition. 



Page 328, line 1 ; for "1847 " read " 1867." 



Explanation of Plate I, line 25; inssert "(?)" after "Lingibla Vanhorn'ii, Miller"; line 28, dele; read 

 " Trenton horizon. Frankfort, Kentucky." 



Expiation of Plate IVk, continued, lino 8; for " Orbiciiloidea pidchra" I'ead " Orbiculoidea Hei-zeri." 



Explanation of Plate I Vf, line 33 ; for " Orbietdoidea pulvhiu " read " Orbiculoidea Herzeri." 



