ART. 6 TROPICAL AMERICAN" APTERYGOTA FOLSOM 13 



outer lobe. Tenent hair three-fourths as long as unguis. Dens (fig. 

 71) three-fourths as long as manubrium, and more than twice as 

 long as mucro. Outer dorsal pinnae of dens 7 (occasionally 6). 

 Inner dorsal pinnae 5. Inner distal pinna extending almost as far 

 as the anteapical tooth of the mucro. Outer distal pinna a little more 

 than half as long as the inner. Mucro (fig. 71) bidentate, with 

 lamella extending to the anteapical tooth, Ventro- apical scale of 

 dens extending as far as the anteapical tooth. Length, 1 mm. 



Panama, April, 1917, J. Zetek, collector. 



Syntypes.—C&t. No. 40391, U.S.N.M. 



CYPHODERUS PINNATUS (Folsom) [New combination] 

 Plate 8, figs. 72-77 

 Borecus pinnatus Folsom, 1923 



This variable species was described from British Guiana, My 

 specimens from the Canal Zone agree with the types except in minor 

 details, as follows : 



The antero-proximal lobe of the unguis is usually smaller than the 

 postero-proximal (fig. 72), though occasionally subequal to the latter, 

 as in the types. At the middle of the inner margin of the unguis is 

 a strong tooth, which is obscure in the types. The outer dorsal pinnae 

 of the dens are 5 ; the inner usually 4 (sometimes 5 or 6). The imier 

 distal pinna (fig. 73) extends to the second anteapical tooth of the 

 mucro; the adjacent outer pinna (fig, 74) extending not quite so far. 

 The teeth of the mucro (fig, 73) vary from 3 to 9 in the specimens at 

 hand (figs. 75-77) ; an apical and two anteapical teeth being constant. 

 Apical tooth relatively small, usually more or less hooked, sometimes 

 almost straight. Anteapical teeth large, subequal, each giving rise 

 anteriorly to a lamella. In addition to the three primary teeth there 

 may be from one to six small secondary teeth; these occur between 

 the two anteapical teeth, in front of the second anteapical tooth, or 

 in both places. To express the number, size, and position of the 

 mucronal teeth, the following formula may be used, in which the 

 primary teeth are indicated by large numerals and the secondary 

 teeth by small ones, beginning with the apical tooth. Thus the 

 formula for Figure 75 would be 111; that for Figure 73, llil. 



In the specimens studied these formulae occurred : 



, . , Length of speci- 



Aiiicronal formula ^^^^ (milimeters) 



111 (fig. 75) 0.8,1.2 



llil (fig. 73) 0.5,1 



mil (fig. 76) 0.5,1 



llUii 1 



llill 1 



lliilii (fig. 77) 1 



111 111 111 1.1 



