(Published May, 1874, In advance of the Report.), 



DESCRIPTIONS OF NEW SPECIES OF GONIATITIDJL 



WITH A LIST OF PREVIOUSLY DESCRIBED SPECIES. 



By JAMES HALL. 



GONIATITES COMPLAISTATUS Hall. 

 Clymenia? complanata Hall, Geol. N. Y. Pt. IV, 1843, pp. 243-4, flg. 100 (5). 



This species was described in the Geological Report of the 

 4th district in 1843 from very imperfect material, and referred, 

 with doubt, to the genus Clymenia. An examination of other 

 specimens, having the same external form, shows them to 

 possess the structure of Goniatites. 



GONIATITES COMPLANATTJS VCLr. PEKLATUS. 



Shell large, subdiscoid ; volutions four or more, embracing, 

 the inner ones being concealed for about half their breadth, 

 leaving a broad shallow umbilicus ; in form the volutions are 

 usually compressed or flattened ; but when not compressed 

 the back is sharply rounded and gradually increasing in 

 thickness for about three-fourths of the width, from which 

 point they are rather abruptly rounded to the inner margin. 

 Septa moderately distant ; less than five chambers occupying 

 a space equal to the width of the volution at the part meas- 

 ured ; there are three saddles on each side of the very small 

 dorsal saddle, each of them rounded ; the ventro-lateral lobe 

 also forming a shallow curve, while the dorso-lateral lobe is 

 somewhat acutely pointed and proportionally deep. 



Surface marked by fine, even, closely arranged, regular, 

 thread-like striae, with a slight backward curvature on the 

 side of the shell, and are again sharply directed forward 

 along the dorso-lateral portion with a deep sinus on the 

 dorsum. 



This shell diners from the C. complanatus principally in the 

 form of the dorso-lateral lobe of the septa, which in this is 



