6 ARKIV FÖR ZOOLOGI. BAND 9. N:0 3. 



from it as well. In addition to this the scales round the body 

 are only thirty-six in P. simoterus. 



Not being able to find any difference between the two 

 genera, Proctoporus and Oreosaurus, I ha ve also compared my 

 specimens with the species of the genus Oreosaurus, but I 

 have failed to identify them with any of the latter as well. 

 They seem to be most similar to Boulenger's species Oreo- 

 saurus Icevis, described in the year 1908 (Ann. Mag. N. Hist. 

 p. 521), distinguished by its quite smooth scales just as this 

 one and also from the same habitat, Colombia. In many 

 other characteristics, however, my specimens differ so strongly 

 from O.- levis that there is no possibility to identify them. 

 To judge from the description, O. Icevis has much longer 

 head and limbs, the interparietal, the occipitals, and the 

 nuchals quite differentiy shaped, only six coUar-shields, not 

 more than thirty-four scales round the middle of the body, 

 the ventrals only in eight longitudinal rows, and so on. 



As mentioned above, I cannot find any constant diffe- 

 rence between the two genera, and I refer this species as 

 well as the following to the genus Proctoporus only because 

 that the latter is of older date than the genus Oreosaurus. 



Proctoporus longicaudatus n. sp. 



Head and limbs short; body rather elongate. Fronto- 

 nasal quadrangular, longer than broad; frontal heptagonal, 

 narrower and shorter than frontonasal, a little narrowed be- 

 hind. Frontoparietals moderate, interparietal large, somewhat 

 broader behind, heptagonal, angular anteriorly, rounded 

 posteriorly, longer than the very broad parietals; a pair of 

 large occipitals and a small median one, forming together a 

 seraicircular anterior margin, enclosing the hind part of the 

 interparietal. A transverse row of four nuchals behind the 

 occipitals, the median larger than the laterals; two large 

 siipraoculars and a postocular, the latter in contact with the 

 parietals, three supraciliaries, the first very large, with an 

 upper horizontal portion in front of the anterior supraocular, 

 reaching the frontal (evidently this plate is formed by a 

 coalasced first supraocular and a first supraciliary); four or 

 five suboculars, the posterior large, the anterior small; a 



