MICHIGAN ACADEMY OF SCIENCE. 



121 



Var. 1. 



Sistruriis catenatus catenatus Rafinesque . — Black or Prairie Rattlesnake. Massasauga, Swamp 



Rattlesnake. 



Body rather stout and short; tail short; rattle rather large; dorsal scales in 23-27 rows, usually 25 

 rows; cephalic plates normal; scutellation is that of the species; dorsal spots usually from 35-41, 3-5 

 of which are on the tail; colors usually darker and the lateral spots more distinct than in the other 

 varieties; occasionally a specimen is found which is entirely black; abdomen yellowish to entirely black; 

 length about 850 m m. From New York to Kansas and north into Canada. Quite common in some 

 of the swamps of Michigan. 



GLOSSARY. 



Anal. Pertaining to or situated near the anus. 



Anal plate. The plate immediately in front of the anus. 



Anus. The opening at the posterior extremity of the alimentary canal. 



Apical pit. The small pit at or near the end or apex of a scale. 



Austroriparian region. In general that part of the United States south of the isother- 

 mal of 77 degrees F, and east of longitude 102 degrees. 



Azygous. Having no fellow, not one of a pair. Single. 



Caudal. Pertaining to the tail. 



Central region. The plains west of the Mississippi and east of the Rockies. 



Cephalic plates. The plates on the top of the head. 



Cervical ring. A color ring or collar on the neck. 



Colubriform. Having a long serpent like form. 



Dorsal. Pertaining to the back. 



Eastern region. The region north of isothermal 77 degrees F and from the Atlantic 

 coast to the Central region. 



Epiglottis. The leaf shaped lid at the base of the tongue. 



Frontal. The central plate on the top of the head. 



Gastrosteges. See Ventrals. 



Geneials. The large plates on the under surface of the chin. 



Gular. The region around and back of the geneials. 



Intemasals. The plates between the nasals. 



Iridescent. Glittering with colors which change in different lights. 



GLOSSARY WITH ILLUSTRATION. 



Fi;,.! 

 CoLLHKIt \ L'Ll'lNUS BaU!D AND GlKAKD. 



Fig. 1.— A harmless snake. 



1. Prenasal. 2. Postnasal. 3. Loreal. 4. Preocular. 5. Postoculars. 6. First row of tempor- 

 als. 7. The largest superior labial. 8. Rostral. 9. The pregeneials. 10. The postgeaneials. 11. 

 The largest inferior labials. 12. The internasals. 13. The prefrontals. 14. The frontal. 15. The 

 supraoculars. 16. The occipitals. 17. Smooth scales. 18. Ventrals. 



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