174 PROCEEDINGS OF THE ACADEMY OF [Mar., 



Food. — This animal will eat almost any animal which it finds in 

 the water or above it, provided it can swallow or capture it. One 

 specimen (No. 6,116) had two frogs {Rana sp.) in its stomach; 

 another (No. 6,260) had a small warmouth (Chcenobryitus gulosus) 

 and a third had other fish remains which were not to be identi- 

 fied. Five of the individuals had internal parasites in the stomach, 

 or about y of all the snakes so troubled were of this species. 



12. Tropidonotus fasciatus (Linnaeus): "Moccasin"; "Water Moccasin"; Southern Water 

 Snake; Banded Water Snake. Fig. 11. 



Ten snakes not of T. taxispilotus were taken in the swamp. These 

 are so variable in coloration and also in scutellation that we hesitate 

 to add to the confusion which obtains in the interpretation of the 

 fasciatus group. Many varieties, subspecies, geographical races, forms 

 or phases have entered the literature of North American Natrices, and 

 these are based mainly on temporal and ocular scutellation, number 

 of scale rows and coloration. These cannot all be assigned faunistic 

 or geographical areas and most of them are as yet likely to appear 

 in one region if a large series be taken. The group is very variable 

 and some of the forms designated may be variants struggling to 

 assume a stable varietal form or geographical place. As yet, how- 

 ever, this gamut of variation apparently appears independent of 

 geographical environments and is almost possible if not actually 

 existent in one region. Therefore, the safer and more conservative 

 course is to place them together and not take any Cratcegus course 

 until more certain of our ground. Intensive localized study and 

 possible breeding as well as extensive geographical collecting with 

 few personal equations seem the hopeful solution of the question. 



Coloration. — The smallest specimen (No. 6,227) in coloration is 

 T. rhomhifera Hallowell. There are 32 dorsal diamond-shaped 

 rhombs from the vent forward. These are formed by oblique bars 

 which connect the upper angles of the lateral row of spots with the 

 alternating dorsal row. The species T. rhomhifera is considered to 

 be a Mississippi Valley and Texan form, yet this specimen certainly 

 accords with Cope's and Brown's descriptions of T. rhombifera and 

 Ditmar's figure of it. Cope held that it rarely had 25 scales, but 

 Brown finds that more than half of his specimens were with 25 rows, 

 and we firmly believe 23 not out of the range of this color variation. 

 Thus, its limit clearly overlaps the supposed 23-25 range of T. 

 fasciatus. The specimen at hand has 23-23-18 scales. The venter 

 has each gastrostege yellow with the border black. Posteriorly, 

 each urostege is black-bordered, thus giving two rows of yellow spots, 



