'^'l89o'."'] PEOCEEDINGS OF THE NATIONAL MUSEUM. 179 



in contact with the eye against two suborbital, and no labials in con- 

 tact with eye. 



From the table which I present below it will be seen that in the 

 whole series no two specimens are alike as far as the plates of the head 

 are concerned. There is hardly an individual with both halves of the 

 head alike, the differences between them in some cases being so great 

 that one side of the head would belong to one genus, the other to 

 another, were we to accept the generic distinctions between Gharina 

 and Wenona, as set forth by Bocourt. Out of twenty specimens, six 

 have four prefrontal plates like the types of plumbea (and bottcv), while 

 eleven (including Bocourt's specimens) have tiv^e such plates, one has 

 seven, one {isabella type) three, and one two. These facts seem to dis- 

 pose of the first distinction between plumbea and isabella^ as well as 

 of the second between plumbea and bottw. As to the upper labials 

 being in contact with the eye, or this organ being surrounded by a 

 ring of small scales, I may state that in the type of plumbea and eight 

 more specimens the latter condition prevails, while in isabella and 

 ten other specimens some of the labials come in contact with the 

 eye. How valueless this character is, however, may be understood 

 from the fact that in one specimen three labials on both sides are in 

 contact ; in another two on one side and three on the other ; in five 

 including the type, two labials touch the eye on both sides, and in two 

 only one labial on each side, while, more conclusive still, one specimen, 

 so far as labials are concerned, is typical Ch. plumbea on one side a nd 

 equally typical Gh. Isabella on the other; No. 4497 b is about similarly 

 situated, though in this only one labial is in contact on one side, and 

 none on the other. This breaks down very effectually the second bar- 

 rier between isabella -And plumbea as well as the third between plimibea 

 and bottom. 



From the above I think it is safe to conclude that Gh. isabella is only 

 an individual variation of Gh. plumbea. 



Two of the distinctions between the latter and Gh. bottom, as tabu- 

 lated by Bocourt, have already been shown to be due to individual 

 variation. A glance at our table will demonstrate that the first char- 

 acter assigned to bottw as peculiar, viz, the presence of internasals, is 

 shared by i^o. 12581, which is otherwise a tolerably average plumbea, 

 and the numerous indications of the anterior nasal breaking up into a 

 prenasal proper and an internasal, as shown, for instance, on the right 

 side of the type of plumbea, proves conclusively to my mind that this 

 character is entirely unreliable. 



There remains now the number of scale rows of the body, which in 

 the type of bottce are said to be 39. In this particular we have no con- 

 necting link as yet between the two species. The commonest number 

 of scale rows in plumbea. are 45, though several specimens have 43, and 

 a few 47 to 49. Whether this gap will be filled up remains to be seen, 

 but until this happens Gh. bottw seems entitled to recognition upon this 

 character alone. 



