THE CERCOPODA 



165 



lidee and the Plectoptera (Ephemeridse), they are very long, some- 

 times over twice as long as the body, and composed of upward of 

 55 joints ; they also occur in the Pan- 

 orpidae (Fig. 177). In the dragon-flies 

 the cerci are large, but not articulated, 

 and serve as claspers or are leaf -like ' 

 (Fig. 180). In a few Coleoptera, as the 

 palm-weevil (Rhynchophorus phvenicis), 

 Cerambyx, Drilus, etc., the so-called ovi- 

 positor ends in a hairy, 1-jointed, palpi- 

 form cercus. Short 25-jointed cercopoda 



are present 

 in Termi- 

 tidae, and 2- 

 jointed ones 

 in Embiidae. 

 The anal 

 cerci are 

 present in 

 the Orthop- 

 tera and, 

 when multi- 

 articulate, 



function as abdominal antennae. They 

 are longest in the Mantidse (Fig. 182); 

 they also occur in the larva of the saw- 

 fly, Lyda (Fig. 183). Dr. A. Dohrn has 

 stated that the cerci of Gryllotalpa are 

 true sensory organs, and Ave have called 

 those of the cock- 

 roach abdominal 

 antennae, having 

 detected about 

 ninety sacs on 

 the upper side 



of each joint of the stylets, which are 

 supposed to be olfactory in nature, and 

 which are larger and more numerous 



B 



FIG. 181. Larva of Sisyra, from 

 beneath. B, an abdominal appendage. 

 After Westwood, from Sharp. 



FIG. 182. Cercopoda (p) of 

 Mantis. After Lacaze-Du- 

 thiers. 



FIG. 



180. End of abdomen of 

 ^Eschna heros, <j? i ur i urosternite ; 

 or, outer, ir, inner styles of the ovi- n 



positor; n, nth abdominal segment; than similar sacs or pits in the antennae 



c, cercopod. 



1 Heymons, however, denies that the so-called cerci in Odonata are such, and 

 claims that they are the homologues of the "caudal processes" (superior terminal 

 appendages of Calvert) , because they arise from the tenth abdominal segment. 



