IS.IG.] 73 



with nearly the same foi-m as the hatter ; and a fourth specimen is a portion of 

 the crown of a tooth, demi-elliptical in transverse section, with the posterior 

 borders elevated but not dentated. 



Had the different forms of teeth above indicated been obtained from different 

 localities, they might have been referred to at least four distinct genera, but 

 having been discovered together, and possessing the same structural appear- 

 ances, I suspect them to have belonged to one and the same species. 



Tlie largest specimen resembling the teeth of Mcgalomurus in its present con- 

 dition, is 1} inches long from the apex, J of an inch broad at base, and 5 lines 

 thick. One of the specimens, which is demi-elliptical in section, is over an inch 

 in length from tlie apex, 8 lines broad at base, and 3i lines wide at the posterior 

 surface. Anotlicr specimen, apparently with the same form as that just indi- 

 cated, in its perfect condition appears to have had the crown over two inches in 

 length, nearly an inch in breadth, and about half an inch in width })ostcriorly. 



5. Crocodilus humilis, Leidy. 



.The species is founded on ten specimens of shed crowns of teeth, apparently 

 of a small species of crocodile. The largest specimen is 7 J lines long and 3^ 

 lines in diameter at base, which is nearly circular. Another specimen is 1 lines 

 long and 2.y lines in diameter at base ; and a third specimen is 6 lines long and 

 Sj lines in diameter at base. These are all moderately curved conical, nearly 

 circular in transverse section, with the two usual internal acute ridges, and with 

 the intervening surfaces slightly striate or nearly smooth. The crown of a pos- 

 terior tooth is compressed, mammillarj' in form, 2\ lines long and 2\ wide at 

 base, with the summit obtuse, and the sides finely and longitudinally rugose. 



6. Trionyx foveatds, Leidy. 



The species is founded on fragments of several costal and sternal plates. The 

 exterior surface of the costal plates is covered with pits, excepting close to the 

 margins ; and the pits are small and round at the vertebral extremity, and gradu- 

 ally increase in size outwardly and become antero-posterioidy oblong oval and 

 reniform. A vertebral fragment of a third or fourth costal plate, a little over an 

 inch in length, is 11 lines wide and 2 lines thick. Small fragments of the sternal 

 plates present an exterior surface covered with broken vermicular ridges and 

 tubercles separated by wide intervals. Fragments of a hyposternal plate are 3 

 lines in thickness. 



1. Lepidotus occidentalis, Leidy. " 



A species proposed on five specimens of thick lozenge-shaped scales, with the 

 root prolonged in the direction of the long diameter. The enamelled surf ice of 

 the scales is smooth and shining. The largest one has its sides about 4 lines 

 long, the smallest one about 2^ lines long. 



8. Lepidotus Haydeni, Leidy. 



A species proposed on a single specimen of a thick oblong square scale, the 

 long sides of which measure 5 lines, and the short sides 3^ lines. The root pro- 

 jects forward from one of the long sides, and the enamelled surface of the scales 

 is covered with parallel square lines. 



This species is named in honor of Dr. Hayden, who collected the remains char- 

 acterized in this paper ; and which remains, I suspect, indicate the existence of a 

 formation like that of the Wealden of Europe. 



Notice of a new Fossil Genus belonging to the Famili/ Blastoidea, from the Devonian 



strata near Louisville, Kentucky. 



By B. F. Shumard, M. D., and L. P. Yandell, M. D. 



The remarkable Crinoid, now for the first time brought to the notice of Palae- 

 ontologists, was discovered by us as early as 1847, in a gray sub-crystalline 

 limestone on Bear Grass Creek, near Louisville, Kentucky, associated with 

 characteristic fossils of the Devonian system. At that time we had observed 

 only detached jjlates of the genus, which did not permit us to recognize its most 



