ZOOLOGY AND BOTANY, MICKOSCOPY, ETC. 
529 
probably another survival of a primitive type of structure. The circu- 
latory apparatus is very elementary, and it is only in the Stomatopoda 
that there is any approach to such a primitive form as the simple tube of 
this remarkable genus. Mr. Thomson has attempted to arrive at some 
conclusion as to the length of time during which Anaspides has been 
isolated, and he thinks it probable that its separation from some marine 
form occurred at a period shortly after the eruption of diabase green- 
stone, which, if Mesozoic at all, must be referred to the beginning of 
that period. It w r as found associated with an Isopod of a very old and 
greatly generalised type, while the very vegetation on the summit of 
Mount Wellington suggests the antiquity of the region. 
Bosminopsis.* * * § — Under the name of B. deitersi g. and sp. n., M. J. 
Richard describes a South American Cladoceran ; this makes the second 
genus to be found in the family Bosminidea. The justification for the 
creation of a new genus is to be found in the structure of the anterior 
antennae, and the number of joints in the posterior antennae, in the 
structure of the post-abdomen, &c. 
Processes of Maturation.! — Dr. V. Hacker gives a particular 
account of the processes of maturation in Canthocamptus staphylinus Jur., 
and compares the maturation in Invertebrates with that in Vertebrates. 
Constancy in the number of chromosomes throughout successive mitoses 
is usually secured by the fact that before the distribution of the elements 
to the two daughter nuclei the number is doubled by longitudinal split- 
ting. But in the second division of the maturation process (in Arthro- 
pods and the salamander) there is a reduction in the number of chromo- 
somes, the doubling and longitudinal splitting being suppressed. The 
first division in maturation occurs in the “ plurivalent ” fashion character- 
istic of reproductive cells, that is each pair of neighbour-elements remain 
at first in close union (vom Rath, Hsecker, Ruckert). This <c pseudo- 
reduction ” implies a suppression of the last transverse division. 
Copepoda of the Rhsetikon Alps.J — Dr. 0. Schmeil has investigated 
the Copepods collected by Prof. Zschokke from the Alpine lakes of the 
Rhsetikon. He describes Diaptomus denticornis Wierzejski, D. bacillifer 
Koelbel, Cyclops albidus Jurine, C. vernal is Fischer, C. strenuus Fischer, 
C. serrulatus Fisher, Canthocamptus rhseticus sp. n., C. zscholchei sp. n., 
and C. cuspidatus sp. n. In the Calanidse a red colour is characteristic, 
due, as Prof. Zopf has shown, to two carotin-pigments. 
Appendages of Copepoda and Cirripedia.§ — Prof. C. Claus has 
been able to show that the two maxillipedes of Copepods are not the 
inner and outer branches of a single (fifth) appendage, but represent the 
fifth and sixth appendages which have lost their exopodites. In the 
larvaB of Cirripedia there is a displacement of the fifth pair, correspond- 
ing to the anterior maxillipedes of Copepods. The fifth pair appear 
medianly in the same transverse plane as the fourth or maxillary 
appendages. The sixth pair, corresponding to the second maxillipedes, 
become the first of the six pairs of curled feet. 
* Bull. Soc. Zool. France, xx. (1895) pp. 96-8 (3 figs.), 
f Arch. f. Mikr. Anat., xlv. (1895) pp. 200-73 (4 pis.), 
j Abh. Nat. Ges. Halle, xix. (1893) pp. 1-40 (4 pis.). 
§ Arbeit. Zool. Inst. Univ. Wien, xi. (1895) pp. 49-64 (1 pi.). 
