1890.] 
95 
[Packari. 
in Catocala, and in the larva of a saw-fly, Croesus septentrionalis , 
in which he discovered an axial retractor muscle which retracts 
the gland, which is everted by the forced flow of the blood into the 
organ. 
As already noticed in our preceding article we have discovered 
a sternal eversible prothoracic gland in the larva of Heterocampa 
marihesia (Cram.). Having previously observed the lateral jets 
of spray ejected by the caterpillars , 1 we have recently been able 
in alcoholic specimens to discover the opening, which is like that 
in Cerura, and occupies the same position. 
While the Notodontians are a somewhat synthetic or general- 
ized group, and, as our recent studies have taught us, probably 
stand at the base of the Bombycine group of families, similar glands 
occur in another group, the Nolidce, whose systematic position has 
been much discussed, but which appear to be in close proximity 
to the Lithosians. But in them these glands are not confined to 
the prothoracic segment alone, but appear to be present in each 
of the thoracic segments, and this may have been the case in the 
more ancestral caterpillars. It should be borne in mind that the 
larvae of Heterocampa marthesia, and of the different species of 
Cerura with their eversible anal plantae, are highly specialized, com- 
pared with the noctuiform larvae of Naclata, Lophodonta, or of the 
European Pterostoma, Ptilophora, Drymonia, Microdonta, etc. 
My attention was called while reading Th. Goosens’ essay enti- 
tled Les Pattes des Chenilles 2 to the statement that in the larva 
of Nola strigula there is at the base of each pair of the thoracic 
legs a button-like outgrowth, with a quite long tubular appendage, 
which appears to furnish a special secretion. “Other Noise,” Goos- 
ens adds, “have glands placed elsewhere, perhaps for an analo- 
gous purpose.” 
I therefore examined my two alcoholic examples of Nola ovilla 
with the hope of finding similar eversible glands. There are three 
such median sternal glands, one on each thoracic segment. On 
the second and third thoracic segments I could easily find just be- 
hind the insertion of the legs a transverse slit or opening, which is 
very broadly triangular or V-shaped. The anterior edge is bent 
in the median line and is the longer, and the posterior edge is 
shorter, and somewhat thickened so as to form a lip, which how- 
ever is not bent like the Other. In one of the specimens the lips 
American Naturalist Sept., 1886, 812. 
2 Ann. Soc. Ent. France, Ser. 6, vii, 1887, 385. 
