AUT. 12 CLASSIFICATION OF CONODONTS ULEICH AND BASSLER 39 



This genus includes a number of species with relations on one 

 side to Lonchodina and perhaps more particularly to Prioniodina 

 and on the other to Prioniodus but with other characters that are 

 distinctly its own. Most of the species have a nearlj'^ straight bar 

 but have a relatively strong and very long denticle near the broader 

 end with a long series of smaller denticles, typically in alternating 

 sizes, behind it. This general arrangement suggests Prioniodus 

 from which HindeodeUa is distinguished b}^ having an anterior 

 denticulated part with 1 to 8 or 10 small denticles developed in 

 front of the main cusp and in lacking the downw^arclly projecting 

 spur although this is simulated by the downward deflection of the 

 corresponding part. However this deflected part is bowed hori- 

 zontally rather than vertically so as to suggest a basketlike expan- 

 sion at the end of a long bar. The division of the tooth into two 

 denticulated parts suggest a relationship to Prioniodina and more 

 particularly to Euprioniodina from both of which it is distinguished 

 by the more slender, long and straighter bar and other peculiarities 

 readily apparent on comparing the illustrations of their respective 

 species. 



HINDEODELLA SUBTILIS. new species 



Plate 8. figs. 17-19 



The species is particularly characterized by the minuteness of the 

 denticles and their decided alternation in size, usuall}' three very 

 minute denticles occurring in the space between two that are much 

 longer yet very slender. Base straight with only a moderate down- 

 ward deflection at the anterior end. Main denticle two or three 

 times as long as those on the bar; in front of it a narrow toothless 

 space and then occurs a grouj) of three or four teeth of which the 

 terminal one is the largest. Specimen represented by figure 18 is 

 supposed to be a variant of the same species. 



Occurrence. — Mississippian (Hardin sandstone) : Mount Pleasant, 

 Tenn. 



Coty pes. —Cat. No. 10985, U.S.N.M. 



HINDEODELLA SIMILIS, new species 



Plate 8, fig. 20 



Similar to H. suhtilis but the denticles on the bar are all of uni- 

 form size without noticeable alternation and the basketlike anterior 

 expansion is of unusual size. At the anterior end the peculiar ar- 

 rangement of the stronger teeth is shown in the figure. 



Occurrence. — ISIississippian (Hardin sandstone) : Mount Pleasant, 

 Tenn. 



Holotype.—C^i. No. 11299, U.S.N.M. 



