ARTHROPODA 



223 



Figs. 228 and 229. — Stalked Compound Eyes. 



Fig. 228. — A grouse locust, Ophiotettix limosina (Orthoptera). 



' The compound eyes (C) are placed on either side at the end of the stalk- 

 like head. (One antenna is missing.) (Natural History Museum, London.) 



Fig. 229. — The stalk-eyed fly, Achias rothschildi (Diptera). 



The lai'ge compound eyes (C) are at the end of unusually long stalks 

 (Natural History Museum, London). 



a crystalline cone and a retinule of 7 sensory cells grouped around a 

 rhabdome (Fig. 138) (Dethier, 1942-43). A more simple variety is 

 seen in the larvae of Tenthredinidffi (saw-flies) and Coleoptera. These 

 usually have two lateral eyes of cupulate shape with a retma formed as 

 a palisade of sensory cells under a lens -like thickening of the cuticle. 

 The retinular cells are arranged in groups of two or three, each 

 group around an elementary rhabdome which is not constructed for 

 the reception of images. More rudimentary forms occur such as the 



Sawfly 



