FAM. MEMBRACID.E 



CHARACTERS 



The family Mentbracida is characterized particularly by the great development of the pronotum 

 which usually conceals the scutellum, often extends over the entire body and sometimes completely 

 conceals the tegmina. This peculiar enlargement of the pronotum often takes curious and grotesque 

 forms. Other family characters are the three-jointed tarsi, antennas minute and bristle-like inserted 

 in front of and between the eyes, tegmina with distinct corium and clavus, veins of tegmina and of hind 

 wings homologous and a hook on the episternum. 



PHYLOQENY 



The phylogenetic position of the families of the Homoptera is still a matter of much contro- 

 versy among hemipterists. Osborn and Van Duzee have placed the Cicadellida in the highest position 

 in the order of taxonomic rank, while Hansen and Kirkaldy make the Fulgorida the culmination of 

 the phylogenetic table. Osborn holds that the Cicadida are the lowest of the homopterous families 

 and considers the Membracida also very primitive while .'\shmead places the Membracida: next to the 

 Fulgorida near the top of the hst. Stal, whose taxonomic work was of a high order, considered each 

 of the modern families as subfamilies, while McGillivray and Baker ranked each as a superfamily 

 with the present subfamihes raised to family position. Interesting contributions to the subject have 

 been made by Reuter, Sahlberg, Goding, Froggat, Ashmead and Distant but no two of these authorities 

 agree on the same taxonomic arrangement. 



Without entering into the discussion of the relative speciahzation and probable relationship of 

 the other famihes, it would seem that the Membracida, as considered from the standpoint of the structure 

 and development of the more iniportant of the physiological systems, must be assigned a very low place 

 in phylogenetic rank. In defence of this conclusion, the following arguments may be offered : 



1. The entire sensory system is very poorly developed. We agree with Hansen that the phylogenist 



should attach much importance to the structure of sensory organs and the character of the 

 antennae. In the Membracida the antennEe are so minute as to be in most cases hardly visible and 

 are but feebly provided with sensory apparatus. The responses of the insects to stimuli are 

 exceedingly slow or entirely wanting. 



2. The wings are extremely generalized. In an earlier paper (Funkhouser igiS) the author pointed 



out that the Membracida are in this respect even lower than the Cicadida, which Comstock and 

 Needham (1899) have pronounced the most conservative of the Hemiptera so far as wing venation 

 is concerned. 



3. The genital organs are very simple. Little progress has been made in developing these structuies 



from the ancient type. 



4. The pronotum, to be sure, is highly speciahzed, but it is hardly logical to vveigh these modifications 



of purely mechanical structures against the more important phylogenetic evidence offered by 

 the sensory, motor and reproductive systems. 



