TROPIDONOTUS 155 



subfasciatus, Werner) the belly is white, with black 

 bars occupying the free edge of each ventral shield. 



A very remarkable variety (var. cettti, Gene) from 

 Corsica and Sardinia (Plate II., second figure) is grey 

 or olive above, with the black markings confluent 

 into more or less regular annuli, which are nearly 

 as wide as the spaces between them ; these annuli 

 are often broken up on the middle line of the back, 

 and alternating; the collar is absent, or is trans- 

 formed into the first annulus, and the upper surface 

 of the head is more or less spotted or blotched with 

 black. This pattern is most distinct in young and 

 half-grown specimens ; in large examples the annuli 

 may break up into spots, disposed with great sym- 

 metry in transverse series. The belly is black, 

 spotted with white. 



A specimen 20 inches long, from Bona, Algeria 

 (Lataste collection), has the posterior half of the 

 head, from between the eyes and behind the post- 

 ocular shields, of an intense black, followed by the 

 usual yellow and black collar ; two light dots close 

 together on the parietal shields. 



Some specimens are entirely or nearly entirely 

 black. In the var. picturatus, Jan, from the Caucasus, 

 the upper parts are sprinkled all over with light 

 dots, and the yellow collar is present ; the belly is 

 grey, dotted with black, and with white spots on 

 the sides. In others the body is black above, and 

 checkered black and white beneath (var. scutatus, 



