78 University of Texas Bulletin 



second lateral lobe, of which half is concealed by the next volution. The 

 siphonal lobe of the second volution is dissected, and the two lateral sad- 

 dles are bifid with simple rounded subdivisions, but the lateral lobes are 

 rounded and undivided. On the third volution the saddles become still 

 more complicated, in general being trifid, but the lateral lobes have little 

 inflection. The siphonal lobe has elongated to its final form but still 

 lacks secondary inflections. In the fourth volution the siphonal lobe is 

 subdivided laterally, and has mature inflections and form. The lateral 

 lobes are slender and trifid, and the lateral saddles are dissected, in general 

 twice trifid. The final volution of the type individual has all elements 

 of the suture dissected (the siphonal lobe was poorly preserved and likely 

 is more dissected than is shown in the drawing) . The first saddle is twice 

 as broad as the first lobe and is broadly bifid. The second saddle is bifid 

 and the second lobe in this individual indeterminate. 

 Number of individuals: about 10. 



TURRILITES WORTHENSIS Adkins and Winton 

 PI. 3, figs. 1, 6 



This common Pawpaw species marks the clay phase in the region from 

 Denton to Johnson County, Texas. It is more abundant in the basal five 

 feet of the formation. The species is rare in the marl transition phase, 

 one individual having been found near Riovista. The species is very 

 rare or missing in the Red River region. 



TURRILITES sp. 



PI. 3, figs. 2, 4 



There are several dextral and sinistral turrilites, preserved in hematite 

 or pyrite, which characterize the Pawpaw clay, and material is being 

 collected for a further study of their structure. In numbers these tur- 

 rilites are abundant and are one of the most striking features of the 

 fauna. They likewise are rare except in the clay facies, and have not 

 been found so far, north of Denton County or south of Johnson County, 

 Texas. Turrilites similar to these species have been found in the Del 

 Rio clay just above the Exogyra arietina horizon (equivalent of Grayson 

 formation) near Waco and Austin, Texas. 



