968 The American Naturalist. (November, 
(merocyte nuclei) come from inwandering supernumerary sperms 
results from the character of the nuclear figures formed in the divis- 
ion of these nuclei. In comparing the cleavage nuclei with the yolk 
nuclei the author finds that the latter have at most half as many 
chromatin loops in the spindle stage; these loops are also thicker and 
shorter. Such reduced nuclei can have come only from sexual cells, 
from sperms in this case. 
In spite of this ingenious nuclear criterion the author cannot affirm 
that all merocyte structures, even in the elasmobranchs studied, arise 
from polyspermy, so that the meaning and fate of such bodies is not 
left in a very satisfactory condition. 
ENTOMOLOGY." 
Iowa Insects.—Prof. Herbert Osborn, of the Iowa Agricultural 
College, has recently distributed three important papers concerning 
Iowa insects. The first? gives an annotated list of the Orthoptera of 
Towa, and the second! is a catalogue of the Hemiptera of Iowa. Both 
are important contributions to our knowledge of insect distribution. 
The third‘ paper adds lists of the Hymenoptera, Lepidoptera and 
Coleoptera of the State. The author considers each of these lists a8 
preliminary, and they doubtless will prove very useful in working up 
more completely the fauna of Iowa. 
Distribution of Spiders.—Until very recently our knowledge 
of the distribution of North American spiders was very incomplete, 
there being practically no catalogues of the species found in given 
localities. Several important papers, however, have lately appeared, 
which add much to our knowledge of the subject. Mr. Nathan Beale 
has catalogued The Spider Fauna of the Upper Cayuga Lake Basin 
in an important paper of over seventy pages, illustrated by five full 
page plates. Three-hundred and sixty-three species are enumerated, 
a large number of which are here described for the first time. Dr. 
George Marx in his annual address as President of the Entomological 
Society of Washington, last year* gave a list of the Araneæ of the 
'This department is edited by Prof. C. M. Weed, Hanover, N. H. 
*Trans, Iowa Acad. Sci., Vol. i, pp. 116-120. 
‘Trans. Iowa Acad. Sci., Vol. i, pp. 120-131. 
*A partial-catalogue of the animals of Iowa. Ames, Iowa, 1892. 
5Proc. Phila. Acad., 1892. 
*Proc. Ent. Soc. Wash., ii, pp- 148-161. 
