288 REPORT UNITED STATES ENTOMOLOGICAL COMMISSION. 
the scutum is, so to speak, cleft in two by the meeting of the prsescutum 
and scutellum in the median line. The flanks of the thorax, or pleurites, 
are often very large, and the episternum and epimerum are broad, oblong, 
or squarish, and these sclerites are sometimes subdivided into au upper 
and lower division (supra- and infra- epimerum or episternum). The 
sternum is often large, flat, and broad ; it is sometimes divided into a 
sternum and prsesternum. 
The wings are usually net-veined, often with numerous longitudinal 
veins, the branches of the subcostal, median, and submediau veins being 
either very long and parallel with the longitudinal axis of the wing, or 
numerous and small (especially in the hind wings of Orthoptera). 
The hind wings are often (Orthoptera and O. onata) broader and 
larger than the anterior pair, the metathorax in such cases being a little 
larger than the mesothorax. 
The abdomen has in this group, including representatives of the 
Neuroptera, Orthoptera, Dermatoptera and Pseudoneuroptera, besides 
a tenth, nearly complete segment, the rudiments of an eleventh uro- 
mere, 138 represented by a tergite forming the supra-aual triangular plate. 
Well developed jointed cercopoda occur in the Orthoptera and Pseudo- 
neuroptera, while the forceps of Porflcula (Dermatoptera) are un- 
doubtedly modified cercopoda. An ovipositor occurs in the Neuroptera 
(Pauorpidae) and Orthoptera. 
The metamorphosis is incomplete in all the orders of Phyloptera ex- 
cept the more recent and higher order, i. e., the Ncuroptera (in Erichson’s 
sense), in which the transformations are complete, the pupa being qui- 
escent and wholly unlike the larva. 
The relative standing of the four orders of Phyloptera is shown in 
the table or genealogical tree of the winged insects on page 295. 
The sequence of the orders, such as we are compelled to adopt in 
writing or speaking of them, is difficult to decide upon. Beginning with 
what on the whole may be regarded as the lowest order, we might first 
take up the Dermatoptera, which are in most respects the most general- 
ized forms, and stand nearest to the Thysanura (Japyx). 
,88 Nomenclatuue of extehnal pakts of Aiithuofoda.— The following terms Lave been devised 
for convenience in anatomical and systematic work on the Arthropods, and aro submitted for the judg- 
ment of naturalists. We have adopted most of them in a monograph of N. A. Phyllopoda, published 
in Hayden’s Twelfth Annual Report U. S. Geol. Surv. Terr., 1883. 
The term arthromere, originally employed in the author's “Guide to the Study of Insects,” in 18G9, 
is now restricted to the body-segments of Arthropods, the term zonite or somite being used for the 
bod 3 '-segments of worms, etc., as well as Arthropods. The “head,” “thorax” and “abdomen” may be 
termed respectively cephalomme, bcenottome (Gr. baino, to •walk, locomotion), and urosume. The head- 
segments aro termed cephalomeres, the thoracic segments bcenomeres, and the abdominal uromeres. 
For the autoume the term ceethopoda, and for the mandibles and maxilla) the previously used term 
gnathopoda is adopted. 
The thoracic legs are termed bamopoda, and Westwood’s term uropoda , applied by him to the terminal 
pairs of feet of the Tetradecapoda, is extended to all the abdominal feet of Arthropods. The basal 
abdominal feet of male Decapoda, modified as accessory reproductive organs, are termed, for conveni- 
ence in descriptive carcinology, go?iopoda, and the jointed anal corci of certain iusocts and of A pus 
are termed cercopoda (*c^p*os, tail; n-ous, troMv, foot). The elements of the ovipositor or sting aro three 
pairs of blade-like appendages which are homologues of the legs; they may therefore be designated as 
o'opoda, as they are chielly concerned in egg-laying. 
