152 IOWA ACADEMY OF SCIENCE 



Scales above and below lateral band with quadrate black spots. 



Greenish or blackish, with three narrow yellow stripes; six 

 series of black spots; scales very rough, the outer row 

 broad. 



Radix B. & G. 



Lateral stripe on second and third row of scales; scales in 19 rows. 

 Superior labials 8; dorsal band yellow margined with black. 



SiRTALIS (L) 



var. dorsalis (B. & G.) 

 Superior labials 7. 



Two series of spots between vertebral and lateral bands. 



SiRTALIS (L) 



Spots large: those of superior row united forming a broad black 

 band. 

 Stripes dull greenish and space between lateral spots often 

 more or less vivid brick red. 



SiRTALIS (L) 



var. parietaUs (Say). 



Spots obscure; space between bands uniform brownish. 



Almost uniform brownish; the spots very obscure but the bands 

 more or less distinct 



SiRTALIS (L) 



var. ohscurus (Cope). 

 TURTLES (testudixata). 



The reptiles of this group form so homogeneous a group as to be readily recog- 

 nized by all. 



Carapace leathery and with flexible margins. 



Trioxychidae. 



Carapace firm and ossified. 



Toes spreading — not closely bound together. 



Tail very long and strong; crested; plastron narrow. 



Chelydridae. 



Tail short and not crested; plastron broad. 



Lower jaw ending in a long sharp point; plastron with 9 or 11 

 plates. 



Cixosterxidae. 



Lower jaw without such pointed tip; plastron with 12 plates. 



Emydidae. 



TRIONYCHIDAE. 



Nostrils rather under the tip of snout; head narrow. 



Amyda Agassiz. 

 (Amyda mutica Lesueur.) 



Nostrils terminal; head broad. 



Aspidonectes, Wagler. 

 (Aspidonectes spinifer Lesueur.) 



