104 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 91 



CONIOPHANES FISSIDENS FISSIDENS (Gfinther) 



Coronella fissidens Guntheb, Catalogue of the colubrine snakes in the collection 

 of the British Museum, p. 36, 1858 (Mexico). 



Diagnosis, — Scales in 21 rows (rarely 19) ; males with supraanal 

 ridges; supralabials 8 (rarely 7) ; ventrals 117 to 132 in females, 111 

 to 130 in males ; caudals 63 to 79 in females, 62 to 84 in males ; ventrals 

 minus caudals 48 to 63 in females, 38 to 56 in males ; a relatively large 

 spot toward each end of ventrals (usually in addition to numerous 

 smaller, scattered spots) ; belly always spotted; median dark borders 

 of dorsolateral light stripe not distinct in front of anus ; dorsolateral 

 light stripe visible a considerable length on neck ; no spots or irregu- 

 larities of pattern in dorsal area between lateral stripes. 



DisciLssion. — The limits of variation of this subspecies are established 

 by Bailey, whose tabulations for specimens from Honduras south to 

 Panama are here utilized in addition to data derived from specimens 

 in the National Museum. I have not utilized his tabulations for 

 specimens from British Honduras, Guatemala, and Mexico, since sev- 

 eral forms are involved in these countries. 



Mexican specimens I have seen are from Teapa, Tabasco (U.S.N.M. 

 No. 46590) , and San Andres Tuxtla, Veracruz. The latter is probably 

 very near the northern limit of the range of the subspecies. Both 

 have higher ventral counts than typical /. fissidens and accordingly 

 show a tendency toward /. 'proterops. Four other specimens examined 

 are from very near Mexico (Piedras Negras, Guatemala, U.S.N.M. 

 Nos. 109720-109722, and one specimen, HMS No. 7353, in the EHT- 

 HMS collection). These are typical and have a regular series of 

 relatively large dark spots near the ends of the ventrals. 



The eight cotypes of /. fissidens,, the scutellation of which is given by 

 Boulenger,- almost certainly include pioterops as well as that here 

 defined as fissidens. So far as available data on these cotypes indicate, 

 the preponderance of characters are of /. fissidens as here defined, to 

 wit: Ventral and caudal counts typical in three, possible in three; 

 scale rows typical in six; supralabials certainly typical in six. The 

 characters indicating proterops are : Ventral and caudal counts typical 

 in two, possible in three; scale rows typical {fide Boulenger) in two; 

 supralabials possibly typical in two. Accordingly I restrict the name 

 to the form here defined as /. fissidens and to that cotype which most 

 closely corresponds with all characters defining the form. 



'Catalogue of the snakes in the British Museum (Natural History), vol. 3, pp. 207, 208, 

 1896. 



