760 



REPORT OF NATIONAL MUSEUM, 1898. 



the third row. The ends of the scales of the vertebral row are some- 

 times darker tipped. Head dark brown, darkest behind, with numer- 

 ous but obscure paler vermiculations. Sides of head i)ale with a 

 reddish-brown band from the rostral plate through the eye to the 

 middle of the last labial. Labials whitish, with black dots on the pos- 

 terior, in oblique rows. Below white, lower labials sparsely black 

 dotted. A pair of pale dots on the common occipital suture. 



This is a snake of rather feeble character. I observed a specimen 

 from Fort Macon, North Carolina, which I owed to my friend, Dr. H. C. 

 Yarrow, for several months in conlinement. It M^as rather inactive. 



The Rhadinwa flavilata has been found along the southern Atlantic 

 coast region from southern North Carolina to southern Florida. It is 

 more common in the latter region than elsewhere. 



Bhadinaa fiavilata Cope. 



HETERODON Latreille. 



Heterodon Latkeille, Hist. Nat. des Reptiles, IV, 1799, p. 32. — Dumkril and 

 BiBRON, Erp. G6n., VII, 1854, p. 766. — Baird aud Girard, Cat. N. Aiiier. 

 Rept., 1853, p. 51.— GtJNTHER, Cat. Col. Snakes Brit. Mus., 1858, p. 82.— Cope, 

 Bull. U. S. Nat. Mus., No. 32, 1887, p. 54.— Boulenger, Cat. Snakes Brit. Mus., 

 II, 1894, p. 1.53. 



Dentition jdiacranterian. Caudal scutella divided ; anal plate double. 

 Eostral plate recurved, with transverse upturned edge aud ilat antero- 

 inferior face. The nine cephalic plates, a loreal, two nasals and ocular 

 plates present, with one or more supplemental behind the rostral. 

 Scales keeled, bifossate. Pupil round. Form robust. Hemipenis 

 bifurcate, the apices with numerous papillose calyces, and separated 

 by a free margin from the spinous portion. Spines numerous, hooked. 

 An enormous diverticulum of the left lung extending to the throat. 



The few species of this genus which are known agree also in having 

 a series of scales separating the eye from the superior labial plates, 

 and in having an azygous plate behind the rostral. The postero-superior 

 aspect of the rostral plate has a keel on the middle line, and there are 

 from three to live, generally four, scales in the first temporal row. 

 The tail is short. The anterior ribs are capable of extension so as to 

 flatten that part of the body, as is done by the cobras of the genus 

 Naja, but the expansion is not so wide, and it has greater longitudinal 

 extent. The postgeneial plates are reduced to a very small size, and 

 are separated from each other by small scales. 



The species of this genus range throughout North America except- 

 ing the Pacific region. They do not extend far into the Sonoran, and 

 are absent from the Lower Californian and the Mexican regions. They 



