ARTICULATA. 185 



Burmeister divides the JRhyncJiota into tribes and families, as follows : 



Tkibe (1). Fam. 1, Pediculina. 



Tkibe (2). Fam. 2, Coccina. 



Teibe (3) Phytopiithiees. Fam. 3, Apliidhia y 4, PsyUodes. 



Tribe (4) Cicadina. Fam. 5, C'lcadellina / 6, Memhraeina / Y, FaJgo- 

 rina / 8, Stridulantia. 



TEfflE (5) Hydeocores. ^(«w. 9, JSfotonectici ', \^., Nepini ', 11, Galgii- 

 lini. 



Tribe (6) Geocores. ^«??i. 12, Ilydrodromici ; 13, Hqyarii ; 14, Pedu- 

 mni J 15, Jfemhranacei ,' 16, Casjnni ; VI , Lycjcwdes ', 18, Coveodes ; 10, 



Westwood, who admits the Homojytera as a distinct order, divides them 

 as follows : 



Section 1. Trimera. Fam.l, Cicadidce ; '^, Fulgondcn ; 3, Cercopid(B. 

 Section 2. Ddiera. Fam. 4:, PsylUdoi ; 5, Apliid(2 ', 6, Aleurodidce. 

 Section 3. Monomera. Fam. 7, Coccidce. 



The Ileteroptera he distributes as follows : 



Section 1. Hydrocorisa, Fam. 1, Notonectidce ;'''i, Nepidm. 



Section 2. Aueocoeisa. Fam. 3, Galgididce ; 4, Acantldidc2 ', 5, /iy- 

 dTom,etridm j 6, Peduviidce j 7, Cimicid(£', 8, Tingidce j 9, Capsidae, j 10, 

 Lygmdm ', 11, CoreidcB ; 12, Scutelle^ndce. 



Fam. 1. Coccidce. The principal genus of this family is Coccus, one of 

 which {Coccus cacti, pi. 80, ^'j/. 54 « J) has been named cochineal in 

 commerce. This family was named Gallinsectes by Latreille, on account 

 of the resemblance which the female bears to galls, neither wings nor 

 articulate structure being present, the inert oval or hemispherical body 

 being attached during life to the branch of a tree. They affix themselves 

 by means of their rostrum, which is inserted so as to reach the sap, and 

 their rudimentary feet when these are present. They resemble the lower 

 Crustacea in having a retrograde metamorphosis, the larvae being active 

 and capable of moving about to select a place upon which to affix them- 

 selves. The young remain for some time beneath the dead body of the 

 female, which is well adapted for their protection. The males are active 

 and winged, and their antennas are longer than in the females. Some 

 genera secrete from the skin a waxen or cottony substance which covers 

 the body, and is often blown off by the wind in little flakes. In some 

 genera the females are active. 



Some of these insects increase rapidly, and are very hurtful to vegetation. 

 Coccus cacti, on account of its beautiful crimson color, is used as a coloring 

 material, and is extensively cultivated for this purpose, particularly in 

 Mexico, its native country. It has been introduced into the Canary 

 islands, Spain, Algeria, and St. Domingo, and it is cultivated in Guatemala 



389 



