NORTH AMERICAN PANISCINI. 



By Ravmdnd 1Ji;an Whitmvksii, H. S. 

 Massachusetts Agricultural College, Amherst, Mass 



INTRODUCTIOX. 



Tlie tribe Paniscini is rather a small one in this cotmtry, con- 

 taining hilt two genera, and eleven s])ecies so far described. 

 The ext-ernal anatomy here given was prepared from our com- 

 monest species — Paniscus geminatus (Say) — added to by com- 

 parison in some respects with the corresjxjnding structures in 

 Opheltes glaucopterus (Linn). It was my intention when I 

 commenced this paper to include a key to the species of Paniscus, 

 but I have been unable to see specimens of all the species, and 

 the entirely inadequate descriptions of several has made it 

 impossible to prepare a key that would be strictly reliable. I 

 have therefore included the original descriptions of the different 

 species here, leaving it to others with better opportunities to 

 prepare the key. 



This ])aijer has been prepared under the supervision of Dr. 

 H. T. Fernald of the Massachusetts Agricultural College, and 

 to him I wish to extend my heartiest thanks for his suggestions, 

 verification of observations, and other assistance in the course 

 of the work. 



EXTERNAL ANATOMY. 



IIKAI). 



Tile head is of medium size and of the hypognathous tyi)e. 

 It is slightly higher than broad, and when viewed from the front 

 appears nearly circular in outline. From above, it appears 

 slightly bi-concave; the anterior concavity being lost at the 

 level of the insertion of the antennae and below them. 



The compound eyes are large, extending from the top of the 

 head to a jjoint almost touching the base of the mandibles. 

 Looking from the front these organs occupy half or slightly 

 more than half of the front of the head; from the side view the 

 eye takes uj) about two-thirds the width. The anterior margin 

 of the eye, about one-third the distance from the top, is sharjjly 

 excavated which is very noticeable. The antenna) are inserted 

 at I he line of these two indentations or very near it. The lateral 

 margins appear nearly straight. Above the point of concavity, 



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