420 TERTIARY INSECTS OF NORTH AMERICA. 



femora with a median longitudinal carina, not very prominent, middle and 

 hind femora much enlarged, the hind pair with delicate spines on only the 

 apical half of the inferior surface. 



Length, 12.4""; breadth of thorax, 2.3 mm . 



Florissant, One specimen, No. 1.508 of the Princeton Collection. 



2. CACALYDUS EXSTIRPATUS. 



PI. 25, Fig. 3. 



Head subrotund, of about equal length and breadth, distinctly con- 

 stricted behind the eyes so as to form with the rapidly tapering thorax a 

 distinct neck ; intraocular part of the head three-fourths the width of the 

 whole ; the surface coarsely granulate. Thorax trapezoidal, fully one-third 

 as broad again at base as at apex, not very coarsely granulose. Legs 

 rather slender, the middle femora agreeing better witli the fore femora than 

 with the hind ; the hind femora much swollen, armed on the inferior sur- 

 face at and a little beyond the middle with six or seven large, coarse, irregu- 

 lar, flattened, spinous denticulations ; the basal third of the same femora 

 lighter colored than the rest of the femur. 



Length of body, 7.25 mm ; breadth of thorax, 2 mm . 



Florissant. Four specimens, Nos. 662S, 10709, 12102, 13311. 



2. CYDAMUS Stal. 



This genus comprises, as far as known, only four or five tropical and 

 subtropical American species. The one which we here add from Florissant 

 can be placed here only provisionally, as it does not agree in many striking 

 features with the modern forms. In particular the body is more robust, 

 not slender and elongate, as in the modern types. With this exception, it 

 has never been recognized in a fossil state. 



CYDAMUS ROBUSTUS. 

 PI. 26, Fig. 3. 



Head and thorax similarly, delicately, and equably granulate, unless 

 the granulations are coarser next the base of the thorax. Thorax a little 

 shorter than broad, tapering rather rapidly to the apex, which is not so 

 broad as the head, the eyes included, but broader than the intraocular part 

 of the head ; outer posterior angles produced to a long, tapering spine 



