322 BRAXSOX AXD GREGER^AMSDEX FORMATIOX OF AVYOMIXG 



Only one specimen was collected. It agrees with M. ohlongus, save in 

 the shape of the anterior end, which is less prominent than in the type. 

 Figure 25 does not represent the lateral ridge as prominently as it shows 

 in the specimen. Figure 11 may he of an internal mold of this species, 

 but there is no way of making this determination positive. 



MYALINA SAXCTI-LUDOVICI (Worthen) 



Plate 19, figure 26 



1873. Myalina St. Ludovici Wortlieii, Geological Survey of Illinois, volume 5, 



page 540, plate 22, figure 3. 

 1894. MyaJina sancti-ludorici Keyes, Missouri Geological Survey, volume 5, 



page 117. 

 1898. Myalina sancti-lifdovici Weller, Carboniferous Invertebrates, page 364. 

 1909. Myalina sancti-ludovici Grabau, North American Index Fossils, volume 



1. page 453, figure 600. 



Six specimens of this species are in the collection. The largest, 20 

 millimeters in greatest length and a little more than 12 millimeters along 

 the hinge line, is almost two-thirds the size of the type. A series of four 

 measurements on the drawings of the tyj^e and on this shell showed: 

 Length of t}^e, 30 millimeters; Amsden shell, 20 millimeters; hinge-line 

 of type, 171/2 millimeters; Amsden, 12 millimeters; end of hinge line to 

 lower side of shell: Type, 25% millimeters; Amsden, 15 millimeters; 

 width of type, 15 millimeters; Amsden, 10 millimeters. The greatest 

 thickness, 10 millimeters, is near the beaks. 



In some of the specimens the beaks project above the hinge line, but 

 the prominence of the umbones makes this almost inevitable when the 

 shells are slightly crushed, and we do not regard this characteristic as of 

 specific value. The specific reference is not considered as certain. 



BULIllORPHA CAXALICULATA Hall 



Plate 19, figure 15 



1856. Bulimella canaliculata Hall, Transactions of the Albany Institute, volume 

 4, page 29. 

 Polyphemopsis canaliculata (Hall) Meek and Woithen, Geological Report 

 of Illinois, volume 2, page 372. 



1882. Bulimorpka canaliculata AVhitfield, Bulletin of the American Museum of 



Natural History, volume 1. page 74, plate 8. figure 41. 



1883. Bulimorpha canaliculata Hall, Twelfth Report of the Geological Survey 



of Indiana, page 367, plate 31, figure 41. 

 1889. Bulimorpha canaliculata Keyes, Proceedings of the Academy of Natural 



Science of Philadelphia, page 300. 

 1898. Bulimorpha canaliculata (Hall) Weller, United States Geological Survey, 



bulletin 153, page 151. 



