i68 



CONNECTICUT GEOL. AND NAT. HIST. SURVEY. 



[Bull. 



Ceresa taurina, Stictocephala inermis and Enchenopa binotata 

 often lay their eggs in buds ; if the buds are not large the eggs 

 may be so deeply inserted as to cause malformations and (in the 

 case of fruit buds) economic loss. 



On the whole, however, it is believed that such injuries are of 

 such rare occurrence that they may be discounted when compared 

 with the ravages of the really important insect pests. 



Dorsal 



crest 



or spine 



Dorsal 



carina Posterior 

 process 



Fig. 15. A Membracid, front and lateral views, showing structures used 

 in classification. Much enlarged. Drawing by Dr. W. D. Funkhouser. 



External Structures and Nomenclature. 



On account of the fact that the specific and generic characters 

 of the Membracidae are largely based on peculiar pronotal devel- 

 opments and other external structures, it is perhaps desirable to 

 call attention to a few of these special anatomical features in order 

 that the taxonomic keys may be easily used. The fact that the 

 insects of this family show such unusual pronotal structures (often 

 extravagantly produced, spined, barbed or branched) has naturally 

 been seized upon by systematists in the description of species and 

 there is no question but that these structures, although apparently 

 of little physiological significance, are quite constant and of con- 

 siderable taxonomic value. Since the structures are in many 

 cases peculiar to the family, there has naturally developed a termin- 

 ology which is not entirely applicable to other homopterous groups 

 and not at once recognizable to the general systematist. 



On the head, the most important points to be noticed are the 

 absence of the froits (which probably explains the absence of the 

 third ocellus), the relative position of the remaining two ocelli 

 particularly with regard to the eyes, the shape of the clypeus and 

 the outline of the head as a whole (Fig. 16). 



The pronotum is usually the only part of the thorax visible. 

 It is inclined to show development in one or more of four ways — 

 posteriorly (to form extensions over the abdomen), anteriorly 

 (producing porrect or other processes), dorsally (in the form of 



