528 THE AMERICAN NATURALIST. 
pp. 484-488, 489-493), who finds in it a natural group, clearly and 
sufficiently characterized by the anterior end and the genital and ex- 
cretory systems to be distinguished from all other distomes. He gives 
a résumé of the known species and adds six new. Almost simul- 
taneously with this has appeared an excellent description of an 
American species by W. G. MacCallum (Journ. of Morph., Vol. XV, 
pp. 697—710, 1 plate). 
The structure and biology of Oxyuris curvula have been studied 
by H. Ehlers (Arch. f. Naturges., 1899; 26 pp., 2 plates). He con- 
firms the previous opinion that the variably long tail of the female is 
a mark of advancing age and not a specific character, and finds that, 
contrary to the ordinarily received view, this species is of pathologic 
importance. Experimentation showed that direct infection is possi- 
ble, if not general, and that the period of development covers about 
three months. 
Towards the analysis of the old group of distomes Stossich has 
recently contributed a study on the dismemberment of the genus 
Brachycelium Duj. (oZ. Soc. Adr. Sci. Nat., Trieste, Vol. XIX, pp. 
7-10), and a second paper on the partition of the genus Echinosto- 
mum Duj. (75., pp. 11-16). 
In some biological observations on Galeodes and Buthus, E. 
Lönnberg (Ofv. Kgl. Vet-Akad. Forh., 1899, No. 10, pp. 277-284) 
records that the poison of the latter was not strong enough to kill 
the former, and that the belief in the self-destruction of the scor- 
pion when surrounded by fire rests on erroneous observation. In 
Galeodes it is the mechanical power of the jaws only that renders it 
dangerous, and this is not sufficient to pierce the human skin. 
Another paper on the fishes of the Caucasus, based on Dr. 
Radde's collections, is published in German and Russian by Dr. S. 
Kamensky, assistant in zoólogy in Charcow. Numerous new species 
of Barbus (Barbel) are described and figured. 
The fourth part of Boulenger's admirable report on the fishes of 
the Congo is now published. It includes Cleopaide, Mormyridz, 
etc., and the descriptions are accompanied by excellent plates. 
