CXX1X 
Mr. Kirkby also, in the ‘Geological Magazine,’ describes three 
insect-wings from the coal-measures of Durham, and considers that 
they probably belonged to insects allied to the Blattide. 
Psyehe helix is well known to all entomologists as being one of 
those interesting species of which the males long remained unknown. 
From the time of Réaumur, naturalists have sought for it in vain. 
Von Siebold especially examined a hundred and fifty specimens, which 
all proved to be females. Latterly, indeed, one or two entomologists 
have described insects which they supposed to be the males of 
P. helix, but there has always been a certain amount of doubt about 
it. Prof. Clauss appears to have been more fortunate, The larval case 
of the male (Zeits. f. Wiss. Zool. vol. xvii. p. 470) is smaller than that of 
the female, and somewhat different in form. The larva itself is very 
similar in the two sexes, while, on the contrary, the pupe differ 
considerably. Prof. Clauss gives a description and figure of the male, 
and whatever doubt may attach to the supposed discovery of this sex 
by other observers, we may now, | think, congratulate ourselves that 
the male of this curious species has been at last discovered. 
The last number of the Zeitschrift f. Wiss. Zool. * contains a short 
paper by M. F. Ratzel on the egg of an Ephemera. He describes 
and figures two curious hemispherical appendages which are attached 
to their flat sides, one to each end of the egg. Leuckart, in his cele- 
brated memoir, “ Ueber die Micropyle und den feineren Bau der 
Schalenhaut bei den Insecteneiern,” had already observed a somewhat 
similar appendage to the eggs of the Ephemeras examined by him, as 
indeed Swammerdam had also done long before; but he considered 
it to be a mass of spermatozoa, one end of which was engaged in the 
micropyle opening. M. Ratzel has, however, observed the formation 
of the appendages in the ovary, which proves that they belong to the 
egg itself. The eggs examined by M. Ratzel have another curious 
peculiarity. A number of fibrous cords, each ending in a circular 
disk, are attached to the egg along two zones, which divide it into 
three subequal parts. He suggests that the object of these curious 
structures is to prevent the eggs from being carried away by the 
current. 
The ‘ Comptes Rendus’ for June last contain an interesting paper 
by MM. Balbiani and Signoret, on Periphyllus testudinatus, which 
* Vol. xviii. p. 99. 
R 
