136 ROCHESTER ACADEMY OF SCIENCE. 



usually grooved ridge, remarkably thin-walled, the ventral cavities 

 deep and narrow. 



An intricately branched shrub 3-4 m. tall, with erect and spread- 

 ing stout stems covered sometimes to the height of 2 m. with very 

 rough dark ashy gray bark, and stout zigzag branchlets, dark orange- 

 green and marked by many large pale lenticels when they first appear, 

 light red-brown and very lustrous at the end of their first season, 

 becoming dark gray-brown the following year, and slightly armed 

 with stout nearly straight bright red-brown or purple lustrous shining 

 spines, long persistent and ultimately ashy gray, 3.5-5.5 cm. long. 

 Flowers during the first week of June. Fruit ripens at the end of 

 September and soon falls. The leaves turn yellow and fall \'ery 

 early in ' the autumn. 



Rochester ; common on both sides of river south of the city, John 

 Dunbar, May, September and October, 1901; Conesus Lake, I\I. S. 

 Baxter, September, 1902. 



Crataegus Laneyi, Sargent, Trees and Slinibs, i. 5, t. 3 (1902). 



Rochester ; low moist banks of the Genesee River in Genesee 

 Valley .Park, C. C. Laney, June, 1899, John Dnnbar, June and 

 October, 1901, C. S. Sargent, September, 1901. 



C. oxyacantha, Linnaeus and C. monogyna, Jacquin, cultivated 

 species from Europe are sparingly naturalized throughout Monroe 

 County, N. Y. 



There are, besides the above list of Crataegus growing without 

 cultivation, about sixty species planted in the parks and park nurser- 

 ies at Rochester. 



Arnold Arboretum, 



Jamaica P/ain, Mass. 



