THE CERCOPODA 



165 



lidse 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- 



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



the cerci are large, but not articulated, 



and serve as claspers or are leaf -like 1 



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



palm-weevil (Rhynchophorus phoenicis), 



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 Embiidse. 

 The anal 



cerci are 



present in 



the Orthop- 



tera and, 



1 ,,. 



Wiieil multl- 



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 we 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 



FIG. ISO. End of abdomen of J 



B 



FIG. 181. Larva of Sisyra, from 

 beneath. , an abdominal appendage. 

 Westwood, from Sharp. 



-or 



FIG. 182. Cercojioda (v) of 

 Mantis. After Lacaze-l)u- 



thiers. 



keros, 9 ; >. urosternite ; which are larger and more numerous 



(n\ outer, i>: inner styles of the ovi- . 



positor; ii, 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. 



