MEMOIKS OF TEE NATIONAL ACADEMY OF SCIENCES. 
25 
and tlie spine-like tenant hair, there is a lamellate, flattened hair. PL XXXYII, fig*. 10, represents 
the end of a thoracic leg of Meterocampa manteo. Besides the iingnis and tenant hair at the end, 
there are two singular, thin, flattened, oval leaf-like setai arising near the middle of the joint. 
The use of the claw and tenant hair as gra])pling organs is quite apparent, but the function of the 
singular lamellate hairs is a matter of conjecture. 
Hints on the origin of the prothoraeic or cervical shield, — Xot only in the wood-boring Lepi- 
doptera, such us the larvns of the Hepialkhe, and the Oossidic, as well as the Sesiidie, is there a 
well marked cervical shield, but also in the grubs of Cerambycidaj, and some other Coleopterous 
families whose larval bore in hard substances, and in such groups this hard, chitinous plate 
serves to ijrotect the base of the head and adjacent i>arts of the body most exposed to injury. 
Developed in the borers of widely different orders, and obviously of direct use to the animal, it 
has probably arisen in response to an external stimulus, an extra quantitj^ of chitiii having been 
developed by the hypodermal cells of the tergal arch of the prothoraeic segment, which by friction 
has become thickened, just as the skin of the sole of the foot in savages becomes thick and horny 
in those accustomed to go barefoot in dry, rough places. 
In the lower lepidopterous families, as the Tineina, Tortricidpe, Pyralidic, as well as in the 
low-feeding Xoctuidm, which hide under stones, such as the cutworms, a well developed cervical 
shield is generally present. 
In the Bombyces, which feed exposed both on trees and on herbaceous plants, the cervical 
shield is rarely even well developed, but there are' sporadic cases of its development, and especially 
of its appearance in the early stages and of its suppression in later larval life, which are of interest 
and merit notice. 
In the Xotodontian genus Cerura, the i>rothoracic segment is unusually broad and flat above,, 
although it is not smooth, chitinous, or polished; whether its use is to support the large lateral 
tubercles or to resist jnessure and friction is a question. 
In the lirst stage of Basylophia anguina there is a small cervical shield (PI. XXXVII, fig. 11c),. 
which bears four glandular setie on each side of the median red dorsal line. 
In Batana integerrima, a small, transversely oblong, consincuous black cervical shield is- 
present in the freshly hatched larva and in the subsequent stages. There is, however, no shield 
or rudiments of one in Edema albifrons or in Eeterocampa and Macrurocampa. 
In the other Bombyces there is no genuine shield, but in the first stage of some forms the two 
dorsal piliferous warts on the prothoraeic segment are more or less enlarged and sometimes- 
coalesced so as to indicate that the shield may have been formed by the enlargement and 
coalescence of these warts. 
The supraanal or suranal plate, — This plate, the^odex of Kirby and Spence, in Bombycine 
and Geoinetrid larvie, both as to its shape and ornamentation, affords excellent characters for 
distinguishing species, and avo have found it of great use, especially in describing Geoinetrid 
caterpillars. It varies much in sha])e and ornamentation in Xotodontida?, also in Attacidie .and 
Ceratocampidie. In Xoctuidm it is not, so far as we know, very characteristic. It seems to be 
especially developed in those larvic Avhich constantly use the anal legs for grasping, while the front 
part of the body is more or less raised. It is thus correlated with enlarged anal legs. 
Morphologically this plate appears to represent the dorsal arch of the tenth or last abdominal 
segment of the body,^ and is the “ anal operculum” or lamina supraanallH of different authors.’^ 
This suranal ]flate is in the Platyptericidje remarkably elongated, forming an apx)roach to a 
flagellum-like terrifying appendage, and in the larva of liglia tan forms a long, prominent sharp 
sx)ine. Its sUaim also in Cerura caterpillars is leather unusual, being long and narrow. In the 
Ceratoeamindm, especially in Anisota, Dryocainpa, Eacles, and Cithei*onia, this iflate is very 
large, the surface and edges being rough and tuberculated, while it seems to attain its maximum 
in Si>hingicampa, being triangular, ending in a bifid point. 
* See my uoto, “The number of abdominal segments in Lepidopterous larvte,’^ American Naturalist, March,. 
1885, pp. 307, 308. 
■^Compare E. Haase, On the constitution of the body in the Blattidm.” Ann. and Mag. Nat. Hist., March, 1890,. 
227-234. Translated from Sitzungsb. Ges. Naturf. Freuude zu Berlin, Jahrg., 1889, 128-136. 
