Weno and Pawpaw Formations 75 



sutures suddenly more crowded at larger end. Ribs consist of evenly 

 rounded, low, annular swellings in a plane nearly perpendicular to the 

 long axis of the shell, more crowded near the enlarged end, almost equally 

 steep on both sides of the annulation, tallest on the venter and on the 

 ventral half of the sides, thence decreasing in height toward the dorsum, 

 where they turn sharply toward the more constricted end of the shell 

 and become obsolete upon crossing the dorsum. Over the more constricted 

 lower end of the shell a suture lies in the lower half of the valley between 

 each two annulations, but in the thicker part of the shell the relation of 

 sutures to annulations is variable; near the thicker end in the type, the 

 sutures are crowded. 



SUTURE: Besides the siphonal and antisiphonal lobes, the sutural 

 elements consist of three lateral saddles and two lateral lobes. The 



Fig. 4. Baculites comanchensis n. sp., sutures of type individual, camera lucida draw- 

 ing, x 8. 



siphonal lobe is bifid, having two slender, rather acute points and a rela- 

 tively broad, low, crenulate, external saddle; this lobe is nearly twice as 

 tall as broad. The antisiphonal lobe is extremely small and simple; it 

 consists of a single long, narrow, rounded point. The first lateral saddle 

 is about twice as wide as the siphonal lobe and is deeply bifid by a rather 

 simple lobule with one central and two incipient lateral points; each of 

 these portions is again bifid. The first lateral lobe is very tall and bi- 

 furcated terminally. 1 The second saddle is bifid and not quite as wide 

 as the first; of its divisions the ventral one is trifid and the dorsal one 

 bifid. The second lobe is broader at the base than the first, and about 

 two-thirds the height; it is bifid terminally. The third saddle is broadly 

 rounded and shallowly bifid. The suture (Fig. 5) is peculiarly simplified 

 and is very characteristic. It is somewhat similar to that of Baculitef, 

 vertebralis Lamarck (Santonian), but differs in having a very simple and 

 reduced antisiphonal lobe and third lateral saddle, and in the greater 

 breadth and simplicity of its first and second saddles. It has even less 

 resemblance to Baculites baculoides Mantell (Vraconian), whose saddle? 



'If the lobes are trifid the fossil belongs to Bochianites Lory; however, the suture 

 agrees better with Baculites. 



