Il. GENERAL HISTORICAL VIEW. 
eee I am obliged to go much into detail in this chapter, not only in order to 
Ll give a summary of our previous knowledge and its defects, but also and particularly 
in order to throw light on a number of very objectionable postulates, reflections and theories 
put forward by Mssrs. A. Giard and J. Bonnier in their two (four) papers. Very short contri- 
butions (by G. O. Sars and J. Sparre-Schneider) are mentioned in the special part. 
W. Sarensky: Spheronella Leuckarti, ein neuer Schmarotzerkrebs (Archiv fiir Natur 
geschichte, 34ter Jahrgang, 1868, p. 301 

322. Taf. X). The author has given a very 
extensive account of this new genus and species, the first form which was discovered of 
this family. He has found females, males, eggs, larve and pups, in fact all stages, and 
on the whole his descriptions are good, but unfortunately the illustrations are rather rude, 
which is indeed a pity, as the species happens to belong to the most difficult group of the 
large genus. I do not think it necessary to point out some slight differences between the 
author's account and my own, e. g. his incorrect statement of the number of joints in the 
antennule of the larve etc., but it must be mentioned that he has overlooked the rudimentary 
antennee (2nd pair) in the male and the female, that his very detailed description of the 
rostrum is not correct, as he has taken the hairs outside the membranous border of the 
mouth for »Radiirfalten« in the membrane itself (p. 303), and that his long description of 
the more solid chitine lists of the rostrum is too diagrammatic. This is connected with his 
quite wrong idea on the maxillule, about which he writes: »Es sind niimlich zwei solcher 
Kiefern vorhanden, welche eingliedrig sind und an ihrem Ende eine Borste tragen« (comp. 
my description below). On the other hand it must be acknowledged that he has found and 
described correctly the legs and the caudal stylets of the female, but in the male he mis- 
interprets the stylets, taking them for a third pair of legs; he has found spermatophores etc. 
Furthermore, his representation of the genital area is defective, and he has overlooked 
receptacula seminis, but he is right in stating that the female has no anus. He also gives 
a somewhat detailed account of the embryology of these parasites, making out their stages 
of development till they appear as full-grown larvae, but this part of the development I have 
