taking labor, and is a valuable addition to the literature of Eco- 
nomic Entomology. The number of subjects described is so large 
that it is impracticable to give an abstract of the report. 
Riley, entitled ** Notes on the 
Thalessa is an Ichneumon fly having 
six and seven inches in length. The eggs are laid in the burrow of 
the larva of Tremex and not in the larva itself, so it is an external 
and not an internal parasite of the larva. The ovipositor performs 
the part of a saw and drills a hole in the bark over the burrow of 
Tremex. Owing to the great length of the ovipositor, it was long a 
question how the insect could reach the bark to deposit its eggs. 
It is accomplished by the insect so manipulating the organ with its 
feet as to form a double coil in a special membrane between the last 
two segments of the abdomen, then curving it over and passing it 
downward so as to reach the wood. In the pupa this ovipositor is 
bent round and along the ventral surface and then backwards again 
along the dorsal surface. 
A '* Human Parasite." — Prof. Eiley mentions in a general way 
the occurrence of parasites upon or in the human body. He mentioned 
particularly the case of a lady in Washington who felt herself stung 
by some insect. In the course of a few weeks she was annoyed by a 
pimple on her neck. When pressed, there was forced from the spot 
a small larva, of some species of bot-fly, but as nothing was known 
of its parent, its identification was impossible. Reference was also 
made to another parasite noticed by a physician of New Orleans, an 
account of which had been given in a late mumber of '' Insect Life.'^ 
— Jos. F. James. 
EMBRYOLOGY. 1 
The Byssus of the Young of the Common Clam(i%« arena- 
ria L.). — During the past summer Mr. Vinal N. Edwards, the well- 
known collector of the U. S. Fish Commission, at Woods Holl, found 
young clams adhering in great numbers to the surface of floating 
timbers in the harbor of New Bedford, Mass. They were associated 
with Ascidians {Moh/ula) in this unusual position, and very naturally 
attracted the attention of so observant a field -naturalist as Mr. Ed- 
wards, who very kindly brought me an abundant supply of speci- 
mens. The masses as they came into my hand were in flakes 
formed of marine algae and earthy matters, sand, and mould, which 
' This Departmenfis edited by Prof. John A. Ryder, University of Pennsyl- 
vania, Philadelphia." 
