170 REPORT OF NATIONAL MUSEUM, 1898. 



arc nearly sraootli, or feebly ridged longitudinally. The frontal, post- 

 frontal, parietal, and suprateniporo-mastoid are always pitted. There 

 is a low longitudinal median ridge of the frontal bone between the 

 anterior parts of the orbits. The olfactory groove of the frontal is 

 narrow, and their lateral walls robust and low. The posterior part of 

 the surangular bone is honeycombed, while the dentary is smooth, but 

 is perforated by numerous small foramina. 



The vertebrai number as follows: C, 8; D., 10 j L., 7; S., 2; C, 36. 

 Thie neural spines of the cervicals are narrower auteroposteriorly than 

 those of the dorsals, except that of the axis, which Is much the longest, 

 but is not more elevated than the others. The hypapophysis of the sec- 

 ond cervical is very low, but those of the other cervicals and of the 

 anterior four dorsals are well develo])ed ; there is a low one on the fifth 

 dorsal. The mutual surfaces of the centra of the second sacral and 

 first caudal are flat. But tliree of the ribs articulate with the vertebral 

 centra, the remainder having the capitular articulations with the 

 diapophyses at increasing distances from their bases. Of the caudal 

 vertebme the anterior 18 have dia])0i)hyses. The first and second have 

 no chevrons, which are present on the following 21. The terminal cen- 

 tra are much compressed. The last abdominal rib is much more robust 

 than the others. It is similarly composed and posteriorly joins the 

 pubes at their bases. The phalanges are as follows: M anus, 2-3-4-3-3; 

 pes, 2-3-4-3. These details are derived from a skeleton in the museum 

 of the School of Biology of the University of Pennsylvania. 



The alligator is characteristic of the Austroriparian region, ranging 

 from jSTorth Carolina to the liio Grande of Texas. I have examined 

 crania of individuals taken in the Nueces River, Texas, and do not find 

 them to difler in any respect from tliose taken in Florida. 



As regards the range of the alligator up the Mississippi, I have 

 gaii\ed the following information through my friend, Mr. Julius Hurter, 

 of St. Louis, who has for many years made a study of the batrachians 

 and reptiles of Missouri. He states that the oldest residents of the 

 southeastern county of that State have no knowledge of the occurrence 

 of the species in that locality. The most northern locality with which 

 Mr. Hurter is personally acquaim ed is Rodney, Jefferson County, Miss., 

 about latitude 32°. 



Dr. Hugh M. Smith,' of the United States P'ish Commission, says 

 that— 



The luaternal alligator iu April or May seeks a sheltered spot on a bank and there 

 builds a small mound. The foundation of the mound is of mud and grass, and on 

 this she lays some eggs. She covers the eggs with another stratum of grass and jnud, 

 upon which she deposits some more eggs. Thus she proceeds until she has laid from 

 100 to 200 eggs. 



The eggs in the course of time are hatched by the sun, assisted by the heat which 

 the decomposition of the vegetable material generates. As soon as they have 

 "chipped the shell," the baby alligators are led to the water by the mother, who 



'Bulletin, U. S. Fish Commission, XI, 1891, p. 343. Washington, 1893. 



