1886.] Entomology. 283 
ENTOMOLOGY. 
Wittaczit on PsyLLIDÆ.!—In 1883 Dr. Witlaczil published his 
researches on the anatomy of the Aphides, and in 1884 on their 
embryology (of which paper we gave an abstract in AMERICAN 
Natura tist, Feb., 1885). He now furnishes an additional con- 
tribution to the anatomy of the Phytophthira, or plant-lice, mak- 
ing the small group of Psyllidze the subject of important re- 
searches; his exposition of the structure of the insect brain being 
of exceptional value. The species examined by him represented 
the genera Psyllopsis, Rhinocola, Psylla, Homotoma, Trioza, 
His methods were teasing in saline solutions, treating with dilute 
acetic acid the fresh and stained animals entire and making sec- 
tions in the Naples way with Jung’s microtome. 
In external appearance the Psyllidz are small (about a milli- 
. meter in length) differing from other families of Homoptera by 
pound eye; 
od, outer decussation ; oes, cesophagus ; , outer medullary layer; e, 
the similarity of both sexes, which are winged and are provided 
with a pair of compound eyes and three simple ocelli, and have 
ten jointed antennz, the two joints next the base short and thick, 
and the terminal joint bearing a pair of bristles. During life the 
antennz are constantly vibrating. Figs. 1, 2 show the male, 
Fig. 1. Fig. 2, 4 ae 
prm, 1.*—Psyllopsis, g, dorsal view, right wings removed. Fic. 2,—The same, 
teral view, wings removed. ces 
a Be Anatomie der Psylliden, von Dr. Emanuel Witlaczil in Wien. Zeitschrift 
 Wissenschaftliche Zoologie, Vol. xL11 (1885), pp. 5602658, and pl. XX-XXII. 
* Explanation of refi : : lobe: an, 
trence-letters in the figures.—a, anus; al, anten >j an, 
abdominal nerve; at, antenna; aés, antennal swelling; c, central body of brain; 
P, crop; es, eye swelling; ga ion, gz, genital hooks; in, ind-intestine 5 
a. issation ; 7, limb nerve ; mzb, mushroom g.v. -o 
sels; m.n, mid-intestine; 724, mid- ibbe df brain; oc, compound eye; och, ocellus; : 
d b om ed , penis; 7e, 
3 $.0€, Sub-cesophageal ganglion; sź, stomach; ventral nerve-cord. Ro- 
man numerals di apap ERDE +. a RESA K abdominal somites. 
