188 



BULLETIN 54, UNITED STATES NATIONAL MUSEUM. 



the anterior marg-in, being .separated in front l)y a di.stance equal to 

 the length of one eye. The liasal article of the peduncle of the lirst 

 pair of antenna^ is larger and a little longer than the .second article; 

 the third article is very slender and about twice as long as the second 



article. The liagellum is composed of about 

 fourteen articles. The first pair of antennse 

 extend a little beyond the end of the pe- 

 duncle of the second pair, to the end of 

 the fourth article of the flagelluni, or two- 

 thirds the length of the first thoracic seg- 

 ment. The first three articles of the pe- 

 duncle of the second pair of antennfe are 

 subequal; the fourth article is twice as long- 

 as the second; the fifth is one and a half 

 times longer than the fourth. The flagel- 

 lum is composed of twenty-five articles. 

 The second antenna^ extend a little beyond 

 the posterior margin of the third thoracic 

 segment. The frontal lamina is cone- 

 shaped, the base of the cone being large 

 and conspicuous, directed anteriorly and 

 slightly concave. The frontal process of 

 the head slightly overlaps the edge of the 

 ))ase of the cone. 



The first, fourth, fifth, and sixth seg- 

 ments are somewhat longer than any of the 

 others. The post-lateral angles of the first 

 segment are very acute. The epimera of 

 all the segments, from the second to the 

 seventh, inclusive, are distinctly separated 

 ofi' from the segments- They are l)road 

 plates occupying the entire lateral margins 

 of the segments. In all, the post-lateral 

 angles are acute, but especially so in the 

 epimera of the second, third, and seventh 

 segments. In all the epimera there is a distinct carina, extending from 

 the outer post-lateral angle to about the middle of the side adjacent 

 to the segment in the last four, but to the inner antero-lateral angle 

 in the first two. The epimeron of the seventh segment is j)roduced 

 posteriorly ])eyond the posterior margin of the segment. 



All six segments of the abdomen are distinct, although the first is 

 partly covered dorsally in the middle by the seventh thoracic segment. 

 The lateral parts of these segments are not separated ofi' from the dorsal 

 portion, but are completely fused. The ternfinal segment is broadly 

 rounded posti'riorly with a small point in the middle. The posterior 



Fig. 173.— ^Ega ventrosa (After 



SCHIOEDTE AND MEINERT). a, 



Frontal margin with both 

 antennae and frontal lamina 



OF ADULT FEMALE. 6, AdULT FE- 

 MALE, c, Frontal margin with 



BOTH antennae and FRONTAL 



lamina of young female, (l . 

 Young female. (All enlarged.) 



