‘26 
MEMOmS OF THE NATIONAL ACADEMY OF SCIENCES. 
The ninth abdominal segment is nnnsually well deve]ope<l in the Attacidne and the Cerato- 
campidm, sometimes, as has been previously stated, bearing a true “caudal horn,” which takes 
the place of tliat usually growing on the eighth segment. In the lthoi)alocera, the suranal plate 
is in general, especially in Hesperidm and Papilionidie, small and rounded, much as in the 
Noctuidie, but in the Nymjdialidie it is more or less si)ecialized, and remarkably so in the larva of 
Keoni/mplia phocion and other satyriues, where it is greatly elongated and forked. (See figures 
in ScuddePs “Buttorllies of New England;” also W. MiilleFs figures of larva of Prepona.) 
The paratial Johen , — These are the homologues of the two anal valves {valmdcv of Burmeister, 
“ the podical plates ” of Huxley) observed in the cockroach, and occurring in nearly all, if not all, 
insects. In Ceometrid larv:e they are full, lleshy, lobe-like, or pai)illiform, bounding the areas on 
each side, and a])pear as if projecting backward from the base of the anal legs. 
In the Ceratocampida* these paranal lobes are not well developed. In the larva of Cerura they 
•are much as in Geometrid caterpillars, where they end each in a seta. 
The paranal forks, — We have already called .attention to these two bristles in our description 
of the larvm of Cerura. (Proceedings Boston Soc, N. H. xxiv, p. o53.) They are well developed, 
arising from the end of a papilla projecting directly backward. Their use has been indicated by 
Mr, John Hellins,^ who refers to a x)air of sharp ])oints underneath the anal dap, “which are used to 
throw the pellets of frass to a distance.” Occurring in Notodontian and other arbore.al catei’xnllars, 
notably the tree-inhabiting Gcometrids, they are wanting in Noctuidie (including Acronycta and 
Catocala), Sjphingidie, and Bhopalocera, as well as the lower Geometrids and the Microlepidoptera, 
and are not developed in the Sphingidie. In Ichthyura (Clostera) they are slightly developed. In 
the Eurox)eau Urapteryx sanibxicata (received from M. P. Chretien) these lobes are \Gvy large, 
l)apilliform, and vSetiferous, and in our Choerodes, etc., they are similarly developed and the 
use of the two setie or the fork is undoubtedly the same as in Cerura. 
The infraanal lobe, — My attention was first called to this lobe or flap' while examining some 
Geometrid larvie. It is a thick, conic.al, tleshy lobe or fiap, ending often in a hard chitinous point, 
and situated directly beneath the vent. In appearance it is somewhat like the egg-gnide of the 
Acrydii, though the latter is thin and flat. Its use is evidently to aid in tossing the pellets of 
excrement away so as not to allow them to come in contact with the body. In a large not iden- 
tified Geometrid worm, which lives on the ash, this flaj) is large and conical, ending in a blunt 
chitinous point. In a large geometer btlongiug to another genus, the tip is shari)er and harder, 
and in what is i>robabIy a larva of Endroi)ia, while the ])aranal forks are well developed, the 
infraanal lobe ends in a stiff bristle. Whether this infraanal lobe is the homologue of the ninth 
urosternite or ventral pl.ate I will not at present undertake to say. 
Glandular seUe . — Among the Notodontidm the freshly hatched larvie of several genera are 
provided with glandular hairs of various shapes. In Datana intefferrima they are clavate; in 
Dasylophia anguina they are clavate, somewhat flattened, and are dark, but clear at the tip,^ while 
ill all the other caterpillars we have observed that the glandular hairs are confined to the body, 
those on the head tapering to a point, and apparently not fitted for secreting a fluid; those on the 
head of Dasylox)hia are glandular, all ending in a slight transparent bulb. 
Other genera of this group will probably on further investigation be found to possess glandular 
.setie in their first larval stages. They occur in the freshly hatched larva of what is probably a 
species of Heterocampa, also in Xadata gibbosa, Ichthyura inclusa^ and Pheosia rimosa. 
It is to be observed that the freshly hatched caterpillars of Ceratosia tricolor Smith are 
])rovided with glandular hairs. They are flattened at the tip, which is slightly tridentate, with 
^Tbe use of these I find explained by Mr. Hellins in his description of the larva of C. bifida in Ihicklor’a Larvte 
•of British Butterfiies and Moths, ii, p. 142, as follows: “At tho tip of the anal liap are two sharp points, and another 
pair underneath, which are used to throw the pellets of frass to a distance. Similar dmigforks are very generally 
present in Geometrid larva", the paranal papilliform tuhorcles being well developed, though we have not seen them 
in use. 
I have noticed a caterpillar of C. borealis in tho process of defecating, and with the forceps pulled off a pellet 
which was held hy tho two spines of the paranal tubercles. Mr. Dyar tells mo he has both seen and heard the 
-caterpillars casting their pellets with the aid of their spine against the side of a tumbler. 
2 PI. XXXVII, fig. 11. Glandular hairs of Dasylophia; a, of body; h, of the head; c, of prothoracic shield. 
