Miscellaneous. 419 
of the narrow linear ones in the equatorial furrow. There is a 
deep notch or sulcus in the extremity of the posterior segment con- 
tinuous with the longitudinal furrow of the ventral surface. The 
equatorial groove does not remain in the same plane in passing 
around the body; but upon the ventral surface, where it is joined 
by the longitudinal furrow, it exhibits a fault, being in fact one 
turn of a spiral. The margins of the equatorial groove are everted 
and present laterally the appearance of tooth-like processes. The 
flagellum is very delicate, and inserted at or near the posterior 
sulcus in the longitudinal furrow. I was only able to detect it 
in specimens killed with osmic acid, I could detect cilia only at 
the posterior sulcus, on each side of which they present a tuft-like 
appearance. 
The eye-like pigment-spots are rather unfrequently present, and 
vary from one to three or four in an individual, being located at 
one side of the longitudinal fissure. The colour of the Infusorian 
is a yellowish green, and its diameter =, inch. It moves with a 
rolling motion about.its dorso-ventral axis, and was mistaken at 
first for a Volvow or zoospore. It is attracted by light, moves 
about freely on the slide, but ceases its motion if the slide be jarred 
or struck. Many of the specimens which had been kept in a large 
dish seemed to have taken on a resting-stage, the endoplasm 
being retracted from the walls of the cuirass, and containing nume- 
rous oil-globules. I was not able to find any of the “ lunate encyst- 
ments” mentioned by Kent, nor could I make out the existence of 
an endoplast. 
The observations of Mr. Carter of Bombay indicate that the gre- 
garious habit of Peridinium may at times render it a potent factor 
in the contamination of drinking-water, and the peculiar taste of 
Baltimore water at times may be due in part to large numbers of 
Peridinia dying and decaying in the pipes.—Johns Hopkins Univ. 
Circulars, March 1884, p. 60. 
How a Carpenter-Ant Queen founds a Formicary. 
Rev. Dr. McCook presented three specimens of fertile queens of 
the Pennsylvania carpenter-ant, Camponotus pennsylvanicus. These 
had been given him by Dr. Joseph Leidy, who had taken them 
during the last summer at Wallingford, Delaware Co., Pa. The 
circumstances under which they were captured afforded a good 
demonstration of the manner in which a new colony of this and 
other species is begun, confirming the speaker’s own observations 
and published statements. One specimen was taken, August 9, in 
a chestnut log; the others, August 14, in the stump of a chestnut- 
tree. ‘They were enclosed within small cavities about an inch in 
diameter, and, curiously, the queens had sealed themselves within 
their nests by closing up the original opening by which they had 
entered, and from which, as a nucleus, they must have cut out their 
resident-room and nursery. If, therefore, they sallied forth to 
obtain food, as they may have done (for Dr. McCook had at various 
