328 APPENDIX. 



9 Resembles the male, but the bands of the tergum are 

 more dilated than those of the male, and the first is in- 

 terrupted by the groove of the oviduct; the second band 

 is reduced to a small lateral spot; the yellow spot at tip is 

 divided by the groove of the oviduct; the venter is imma- 

 culate, and posterior thighs are piceous on the inner side. 



Length rather more than three-tenths of an inch. 



This species is very closely allied to the dorsigera and 

 gigas, but more particularly to the former; it is much 

 smaller than the gigas, and differs from both in many re- 

 spects, and more obviously in the circumstance of the an- 

 terior margin of the collar being black, with an abbreviated 

 yellow line on the submargin. 



I observed this species running actively over the sur- 

 face of a rafter in a barn, veiy busily feeling with its an- 

 tennae for a proper situation to deposit its eggs. Having 

 found a suitable place, the insect, after some exertion, sud- 

 denly disengaged its oviduct from the groove and valves, 

 and gradually thrust the instrument into the wood, nearly 

 to the base; then having for a short time remained at rest, 

 probably in order to protrude the egg, the oviduct was 

 withdrawn, adjusted in its dorsal groove; and the insect 

 proceeded again as before, in search of another spot suitable 

 for its purpose. I could not ascertain the kind of larvae, 

 within the wood, that received these eggs. 



PSILUS, Jur. 



P. brevicornis. Black, polished, immaculate ; tibiae and 

 tarsi piceous. 



Inhabits St. Peter's river. 



Sntennse short, first joint much elongated, second joint 

 longer than the remaining ones, which are subcylindric- 



