602 
8UMMARY OF CURRENT RESEARCHES RELATING TO 
of classification of the Amphipoda Hyperiidea ; gives morphological 
notes on the group he has especially studied, and concludes with a 
monographic account of the genera and species of the Oxycephalid®, in 
which there are ten genera, and the Xiphocephalidse, in which there is 
only one. 
Bosmina.* — Dr. 0. E. Imhof makes an appeal for specimens of 
species of this genus of the Cladocera, of which he proposes to write a 
monograph. Twenty-nine species and four varieties have already been 
described, and it is important to have exact information as to their 
geographical distribution. 
Organization of Cyprides.j — Prof. 0. Claus has taken up the study 
of Cypris, as no sensible addition to our knowledge of the Cyprides has 
been made since 1854, when Zenker published his monograph. The 
ventral nervous cord is elongated, and contains five pairs of ganglia. 
The anterior portion of the brain gives off nerves to the tripartite 
frontal eye, and has a particularly strong coating of ganglionic cells. 
The frontal eye has three closely connected pigment-cups, each of 
which is occupied by some sixteen to twenty cells, into which the nerve 
fibres enter, beneath a nearly spherical lens. 
The endoskeleton is represented by a broad, indistinctly bipartite, 
chitinous plate, to which pairs of muscles for all the limbs of the trunk, 
as well as the second pair of antennae are attached. The alimentary 
apparatus commences with a rather narrow atrium. Zenker’s “ rake-like 
masticating organs ” are situated at the bottom of this atrium, and 
belong, as a sort of hypopharynx, to the labium. The gizzard is not, as 
Zenker supposed, free, for its larger hinder portion is united with the 
intestine ; the smaller anterior portion is capable of a forward and 
backward displacement which calls to mind the motor mechanism of the 
gizzard of the Decapoda ; but it affects only the dorsal wall, the strong 
convexity of which projects into the lumen, beset with rows of pointed 
teeth, and acts like a rasp against the concave ventral wall, which is 
also densely armed with points. The mid-intestine is divided by a deep 
constriction into two sections, the anterior of which surrounds the 
throat-like opening of the gizzard, and gives off two hepatopancreatic 
tubes into the interspace of the fold of the shell. It contains a very 
deep glandular epithelium, and must, as the stomach, have the function 
of digesting albuminous foods. 
Both the antennary gland and the gland of the second pair of 
maxillse are well developed in Cypris , but the former is placed in the 
shell-cavity, and must, therefore, be called the shell-gland. The gland- 
duct consists only of a series of perforated cells, the nuclei of which are 
of enormous size, and emit above and below digitiform branches, each 
of which represents only a single perforated cell. 
The complicated penis represents a metamorphosed pair of limbs, 
while the external genitals of the female are probably the basal joints of 
a pair of limbs. The oviduct is much coiled, and the duct of the 
receptaculum is spirally twisted like a watch-spring. 
* Zool. Anzeig., xiii. (1890) pp. 359-61. 
f Anzeig. K.K. Akad. Wiss. Wien, 1890, pp. 1-6; see Ann. and Mag. Nat. 
Hist., vi. (1890) pp. 108-12. 
