igoi] Botany. 179 



Shell compressed-convex, ovately subelliptical, much longer 

 than high, higher than broad, and very inequilateral. Anterior 

 end short, rounded ; posterior end much longer than the anterior, 

 its extremity obliquely subtruncate above, produced and somewhat 

 narrowly rounded below ; beaks placed in advance of the mid- 

 length ; posterior umbonal slopes not at all angulated. 



Surface marked only with numerous concentric lines of growth. 

 Hinge dentition, muscular impressions, and pallial line unknown. 



Approximate dimensions of the specimen figured : — Maximum 

 length, sixty-eight millimetres ; greatest height, thirty-seven 

 millimetres ; maximum breadth or thickness, twenty-four 

 millimetres. 



The slight distortion and somewhat slickensided movement 

 to which the specimen has been subjected has so displaced the 

 normal position of the valves that the marginal outline is not as 

 distinctly defined as might be desired, and the beaks are no 

 longer quite opposite 



As compared with U. Nanainioensis, U. Hiibbardi'xs a much 

 more convex shell, with distinctly angular or subangular posterior 

 umbonal slopes, and it is much more attenuate posteriorly. 



For the two drawings which are reproduced in this paper, the 

 writer is indebted to his friend and colleague, Mr. ].. M. Lambe, 

 F.G.S. 



Ottawa, December 4th, 1900. 



BOTANY. 



Mr. C. Guillet, whose paper "On the Late-flowering of Native 

 Plants," is announced for February 12th, in the Programme of the 

 Club's Winter Soirees, would be glad to receive notes and 

 records of observation on the same subject by other members of 

 the Club. 



This notice should have been announced at the last meeting 

 of the Club but was inadvertently omitted. 



H. M. A. 



