Occasional Papers of the Museum of Zoology 35 



what forward as in 0. zvalkeri. There are only four striae 

 or sulci above the lowest margining one on each side. Of 

 these, the second one is characteristic, being parallel to margin 

 and ending abruptly in front, not curving and continuing 

 upward as do the others. (See PI. 16, Fig. 105.) 



Segmental suture deep, as usual, a little excurved oppo- 

 site the pore which lies in about the middle of the darker 

 region of metazonite. Metazonites of middle segments striate 

 only well beneath ; but up the sides and across dorsum rough- 

 ened by numerous somewhat irregular and very weak longi- 

 tudinal rugae or folds which may, with proper lighting, be 

 seen with the unaided eye. 



Last tergite characterized by having the caudal portion 

 sharply set off by a transverse furrow and depressed below 

 level of anterior region; also more strongly roughened, finely 

 reticulo-rugose, just caudad of the furrow. Tergite rugose 

 •on the sides. Anal valve with mesal borders elevated as usual. 

 Anal scale of usual general form, rather broad, with a broad 

 median longitudinal elevation on keel. 



Number of segments, 58. 



Length, about 105 mm. ; width, 7.5 mm. 



British Guiana : Sand Hill Forest. In Calladium root 

 mass. Aug. 22, 1914; F. M. Gaige. One female. Holotype, 

 M. C. Z.. 5.109. 



Orthoponis sp. 



In the collection are several immature females and males 

 of an uncertain species. 



British Guiana: Forested Sand Hills. Aug. 17 and 18, 

 1914: F. M. Gaige. 



