Weno ami Pawpaw Formations 139 



HELICOCRYTPUS MEXICANUS Bose 



1910: Helicocryptus mexicanus Bose, Inst. Geol. Hex., Bol. 25, p. 140, pi. 46, figs. 1-6; 

 pi. 47, fig. 1. 



A single individual lacking the mouth but otherwise well preserved and 

 agreeing with the original description, was determined by Dr. Bose as be- 

 longing to this species. 



LOCALITY : 714, near Fort Worth, Texas, in the basal Pawpaw clay. 



NERITA .p. 



PI. 10, fig. 28 



This fossil is found in the "buff marl" of the Weno brickyards at Gaines- 

 ville, Texas, in association with Trochus laticonicus, Venericardia weno- 

 ensis, and other fossils listed in the geological section of this locality. 



NERITINA .p. 

 PI. 10, fig. 27 



This small calcitic fossil is one of a group of peculiar small fossils as- 

 sociated in the "buff marl" of the brickyard pit, near Gainesville, Texas. 

 The others are Trochus laticonicus Adkins, Nerita sp., Venericardia weno- 

 ensis Adkins, Placosmilia spp., Trigonia clavigera Cragin, Leioddaris 

 spines, Corbula littoralis Adkins, Pecten sp. and numerous widely distrib- 

 uted Weno fossils. 







ANCHURA MUDGEANA White 



PI. 10, figs. 39-40 



1879: Anchura mudgeana White, llth Ann. Kept. Geol. and Geogr. Surv. Terr., p. 312, 



pi. 7, fig. 3a-b. 

 1889: Anchura (Drepanocheilus) mudgeana Hill, Geol. Surv. Texas Bull. 4, p. 19. 



1894: Anchura mudgeana Hill, Bull. Geol. Soc. Amer., vol. 5, p. . 



1918: Anchura mudgeana Stephenson, U. S. G. S. Prof. Paper 120-H, p. 141. 



This common species of the Weno shale at Denison and Gainesville has 

 not been found outside the Red River region, to my knowledge. It is con- 

 spicuous in the ironstone and blue shale layers of the Weno in association 

 with a large nacreous fauna including Corbula spp., Nucula spp., Turritella 

 sp., Cerithium sp., Natica sp., and others. It differs from Anchura pro- 

 labiata White in having a single instead of a double lip ; and from A. ruida 



