250 THE CANADIAN NATURALIST. [Vol. viii. 



in thickness, the outer constituting the remainder of the axis. 

 The scalariform tissue of the latter was radially arranged, with 

 the individual cells quadrangular in cross section. A few small 

 radiating spaces partially filled with pyrites obscurely represented 

 the medullary rays, which were but feebly developed; the radia- 

 ting bundles, passing to the leaves, ran nearly horizontally, but 

 their structure was very imperfectly preserved. The cross section 

 when weathered, showed about twenty concentric rings; but 

 these under the microscope appeared rather to be bands of com- 

 pressed tissue than true lines of growth. The thick inner bark 

 was replaced by sandstone, and the outer bark represented by 

 Structureless coal. On a small portion of one of the roots the 

 author traced the remains of stigmarioid markings. From the 

 above characters the author identified this tree with Diploxyhm 

 of Corda, and stated that it was the first well-characterized 

 example of this type of Sigillarians hitherto found in Nova Scotia. 

 The author compared the structure of this stem with that of 

 other Sigillarians, and remarked that it seemed to come within 

 the limits of the genus SigUlaria, but to belong to a low type of 

 that genus approaching Lepidodendron in structure; those of 

 the type of S. elegans, Br. and S. spinulosa, Renault, being- 

 higher in organization, and leading towards the still more eleva- 

 ted type described by him in 1870. He further discussed the 

 supposed alliance of these trees with Gymnosperms, and the 

 probability of the fruits known as Trigoiwcarpa being those of 

 Sigilfarla, and expressed the opinion that the known facts tend 

 to show that there may be included in the genus Sigilhtria, as 

 originally founded, species widely differing in organization, and 

 of both Gymuospermous and Acrogenous rank. — Proc. GeoL 



Soc, Land. • 



At its last session, the American Congress made an appropria- 

 tion of $18,000 for a Commission of three skilled Entomologists 

 to investigate and report on the ravages of the Rocky Mountain 

 locust, and to suggest means for their prevention ; to be appointed 

 by the Secretary of the Interior. — Am. N~at. 



We have received a preliminary announcement of a Scientific 

 Expedition around the World, organized on rather a unique 

 plan, to be conducted by a faculty of ten. There will be accom- 

 modation for sixty to eighty students. For farther information 

 we would refer our readers to James O. Woodruff, Indianapolis, 

 Ind., or Prof. W. L. B. Jenney, Chicago, 111., or Prof. J. B. 

 Steere, Ann Arbor, Mich. — Ibid. 



Published April 6th, 1877.J 



