NO. 1690. ON EDB8TUS AND RELATED GENERA— HAY. 53 



these fossils are being described by Dr. George H. Girty, of the U. S. 

 (jeological Survey. Doctor Girty has verj^ kindly furnished me 

 some information regarding these fossils and their relationships. He 

 writes me that the specimens of Lissoprion were obtained from phos- 

 phate beds of from GO to 100 feet in thickness and placed near the 

 middle of the Preiiss formation. The fauna has a facies strongly 

 unlike anything known from the Pennsylvanian of eastern North 

 America, and man}^ features tend to ally it with the upper Carbo- 

 niferous faunas of eastern Europe and Asia. In fact Doctor Girty 

 feels little doubt that it is equivalent to a part of the Gschel stage 

 of the Russian section. Some of the characteristic fossils of the phos- 

 phate fauna are Chonetes ostiolatus, Pugnax weeks/, Amhocoelia 

 arciiata, Nucula inontpelierensis, Yoldia mcchesneyana, Leda ohesa, 

 Plagioglypta canna, Omphalotrochus ferrieri, O. conotdeus, and 

 Gastrioceras simtdator. The genus Productus is poorly represented 

 in the phosphate fauna, but contains four species closely related 

 and perhaps identical with forms occurring in the Gschelian of 

 Europe. These species, with the species of OmphalofrocJins and 

 others occurring in the overlying strata of the same formation, are 

 the forms in which the affinities with the Russian fauna are especially 

 manifested. 



In the case of the specimen which furnished fig. 1, pi. 14, the rock 

 split in such a way as to expose the right-hand side of the first 

 five large teeth, those at the termination of the shaft, and the left 

 side of the fifth of these (counting from the end), two others suc- 

 ceeding this, and several small teeth of an interior whorl, as well as 

 a part of the shaft. The figure has been prepared by combining two 

 photographs, that of the left side having been reversed. The desig- 

 nation of the sides as right and left is made on the assumption that 

 the base of the spiral, the larger end, was directed backward in the 

 animal, a view that may require modification. The 5 or 6 teeth 

 seen in the lower part of fig. 1, pi. 13, formed probably the begin- 

 ning of the second whorl, no remains existing in the specimen of 

 the first or innermost whorl. Some traces are found in the matrix of 

 the remainder of the second whorl. The large teeth would then 

 belong to the third whorl. 



It will be observed that the shaft of the specimen extends back- 

 ward (toward the left) some distance bej'ond the last tooth produced, 

 and the same will be found to be true of the species called by Dean 

 Edestus lecontei. The last tooth present can hardly have been the 

 last one that would have been developed had the animal lived longer, 

 for this tooth lacks much of having the size of the teeth of the type 

 specimen. In this the largest tooth has a height of 36 mm. and a 

 width of 17 mm., while the last tooth of fig. 1, pi. 14, has an axial 

 height of 30 nun. and a width of 11 mm. 



