Zoology. 651 
those of gapperi, consists in the openly-communicating loops. 
e upper molar series measures 4.5 mm. on the crowns, 4.8 mm. 
on the alveole. The lower molar series measures 4.4 mm. on the 
crowns, 4.6 mm. on the alveole, 
I take great pleasure in bestowing upon this handsome mouse the 
specific name dawsoni, as a slight recognition of the indefatigable 
zeal of its discoverer, the distinguished éxplorer and geologist, Dr. 
Geo. M. Dawson, who has added so much to the fund of knowledge 
relating to Northwestern Canada.— C. Hart Merriam. 
ZOOLOGICAL NEws—GENERAL.—F’, Koenike records (Abh. Nat. 
Ver. Bremen., X.) the finding of the Myriapod Geophilus sodalis in 
a hen’s egg, : 
Protozoa.—Dr. A. C. Stokes givesa generic synopsis of the 
sedimentary fresh-water peritrichous Infusoria in the American 
Monthly Micros. Journal, IX., p. 59. 
C@LENTERATES.—Dr. Benjamin Sharp records (Proc. Acad. 
Nat. Sci, Phila., 1888, p. 82) the finding of the common 
etenophore, Mnemiopsis leidyi in a pond of fresh water in Nantucket. 
They appeared perfectly healthy and active and were phosphores- 
cent at night. e pond was occasionally opened to the sea to 
allow the escape of the perch which bred in it; but at the time of 
the observation the water in which the jelly-fish*wer® swimming 
was perfectly fresh to the taste. 
` Worms.—Dr. Otto Seifert has a paper on the pathological effects of 
the human parasite, Ankylostomum duodenale, in the Verhandlungen 
of the Phys. Med. Geselischaft, of Würzburg (XXI.). This is the 
worm which was first brought into prominence at the time of the 
building of the St. Gothard tunnel, when it produced the disease in 
the workmen known as Gothard or tunnel disease. 
_ Mortuscs.—Dr. W. D. Hartmann communicates to the Proceed- 
ings of the Philadelphia Academy (1888, pp. 14-56) catalogues of 
distribution of the species. : 
Mr. B. H. Wright describes (Proc. Acad. Nat. Sci., Phila., 1888, 
p. 113) seven new species of Unionide from Florida. Each 
specific name is dedicated to some friend of the describer. 
r. E. von Martens describes (Stzb. Gesellsch. Naturf. Freunde, 
Berlin, 1887, p. 106) two new species of Unio (U. percompressus 
and U. microdon, from Guatemala. 
