G. GENERAL NATURAL HISTORY AND ZOOLOGY. 341 



ty. The layer of flesh is not so thick, however, as we expect- 

 ed, and only slightly masks the form of even the detailed 

 sculpture of the sponge. It is not nearly so thick and spongy 

 as it is in another species of the same genus which we dredged 

 off the coast of Portugal." 12 ^1. 



FRUSTULIA SAXONICA. 



Dr. Woodward, U. S. A.,has published an article upon the 

 markings of Frustulia saxoiiica^ illustrated by copies from 

 photographs, and correcting some misstatements and misap- 

 prehensions in a previous communication by Mr. Hickie. It 

 will be read with interest by all those engaged in testing ob- 

 jectives by means of the Biatomacece. Monthly 3Iicroscop- 

 ical Journal^ December^ 1875. 



AULACODISCUS OREGONUS. 



Dr. Christopher Johnson gives a very excellent represen- 

 tation of Aulacodiscus oregomis with two centres, and he 

 inclines to Vrolick's opinion tliat this and other similar 

 monstrosities are an evidence of the action of an excessive 

 developmental potency. It is very well known that the spo- 

 rangial frustule is sometimes, in cases of conjugation of the 

 Diatomace?e,the result of a differentiation of the endochrome, 

 or internal contents of a single parent frustule ; and in the 

 gemmiparous increase the division always occurs, primarily, 

 in the central nucleus ; in either case it would not be diffi- 

 cult to account for an occasional monstrosity. American 

 Journal of Microscopy^ June^ 1876. 



EOZOON CAXADEXSE. 



Mr. W. S.Dallas has translated Otto Hahn's "Micro-geo- 

 logical Investigation of Eozoon Canadensey In this paper 

 Halin comes to the definite conclusion that the Eozoon is a 

 myth founded on a mistaken conclusion as to the micro-geo- 

 logical character of certain serpentines. A2)7Hl, 187G. 



FUSISPORUM SOLARIA. 



In reference to this fungus, which commonly appears on 

 diseased potatoes in company with Peronosj^ora infestcms, 

 Mr.W. G. Smith states that the resting spores are about 

 5ToT7 of an inch in diameter, and are almost always accom- 



