1220 General Notes. [ December, 
ENTOMOLOGY. 
OCCURRENCE OF COLIAS NASTES IN THE PAMIR MOUNTAINS.—In 
the Investia of the Russian Geographical Society is a paper by 
M. Grum-Grzimailo, who has journeyed, says Nadure, in the 
mountains north of the Alay region of the Pamir, in Central 
Asia.’ Ona rich Alpine pasturage, where Kirghizes are in the 
habit of staying, he found Colas eogene, Arctia erschoffi, etc., 
which are common almost exclusively to the Himalayas and the 
Southwest Thian-Shan. On the plateau between the Kara-Su and 
the Aram, with other rare Lepidoptera were species of Colias and 
Parnassius. On the Dje Kaindy pass, the Lycaenz were numer- 
ous, so that in the space of three meters the author found fifteen 
species of them, of which three were unknown to him. Another 
find of great interest was that of C. mastes: The late Mr. Fed- 
chenko had alrec dy caught one female butterfly, which was de- 
termined by M. Erschoff as Colias nastes. This species having 
been found formerly only in Labrador and Northern Lapland, the 
determination remained doubtful, the individual having been but 
a female. M. Grzimailo has caught a number of both males and 
females, which really proved both to belong to C. xastes. The 
writer says it remains now to explain the strange extension of 
this species. He does not seem to be aware that several (nine 
species) other Labrador Lepidoptera occur in the Altai mountains 
of Northeastern Asia. 
Tue Eye anp Optic Tract or Insects.—In his essay on this 
subject Dr. S. J. Hickson (Quart. Journ. Micr. Science, April) 
describes in detail the eye and optic tract of the flesh fly (Musca 
vomitoria). The pseudo-cones he has found to be composed of 
four cells, with their nuclei situated internally, each one contain- 
ing a large watery or albuminous vacuole, which serves the same 
purpose, and is morphologically homologous with the crystalline 
cone of the “eucone” eyes. There are six retinule cells, each 
possessing a nucleus situated in that part of it which lies imme- 
diately behind the pseudo-cones, and in some cases an additional 
nucleus, situated about half-way down. He has figured for the 
first time the interommatidial tracheal vesicles which have been 
previously observed by several investigators. In the optic tract 
he has described three ganglia—the opticon, epi-opticon and peri- 
opticon. The last of these is composed of a number of small 
cylindrical elements of a tissue composed of a sponge-work of 
_nerve-fibrilla, which he has called a “neurospongium.” The 
_ Opticon and epi-opticon are present in all insects, and in most of 
ae 
the higher Crustacea. The peri-opticon appears comparatively 
ate in development, but is never found even in the adults of 
eri-opticon, when present, is usually composed of a num- 
| | elements, which- partially fuse in Æschna and 
