No. 2. J MISCELLANEOUS. 12.^ 



in the bay or estuary then representing the Ottawa river, northern 

 marine animals were imbedded in deposits into whieh was alsa 

 washed the debris of neighboring hind, and of fresh water streams. 

 The climate at the time was colder than at present, and the area 

 of land less, so that if this Estheria still lives, it is most likely to 

 be found in the vicinity of the Arctic coast. " 



This Estheria is entirely unlike any northern American or 

 European species, differing decidedly from Estheria morsel or E, 

 cnldweUi and E. darhii It rather approaches E. jonesii from 

 Cuba in the form of the shell and style of marking of the valves. 

 It does not resemble closely any of the fossil forms tigured in 

 Jones' Monograph of fossil Estheriag. The markings, however? 

 present some resemblances to E. middtndorfii Jones, but differ 

 in the want of anastomosing cross wrinkles between the ridges. 



One valve and portions of others were preserved; but none of 

 them show the oeaks (umbones), though the form of the remain- 

 der of the shell indic-'tes that they were situated nearer the middle 

 of the valve than usual, i e.. between the middle and the anterior 

 third of the shell. The shell is deep, probably more so than in 

 E. jonesii, though the valves have evidently been flattened and 

 and somewhat distorted by pressure, but apparently the head-end 

 was more truncated than in E. jonesii, as the edge of the 

 shell and the parallel lines (or ridges) of growth along the head- 

 end are below bent at right angles to the lower edge of the shell. 

 The raised lines of growth are very numerous and near together; 

 they are of nearly the same distance ;ipart above near the beaks 

 as on the lower edge. The very numerous lines of growth are 

 thrown up into high sharp ridges, the edges of which are often 

 rough, finely granulated, and often the valleys between are rugose 

 on the surface. In one or two places a row of papillae for the 

 insertion of spinules may be seen where the shell has been well 

 preserved, and between many of the lines of growth there are 

 irregular superficial ridges. Length 10 mm. ; depth 7.5 mm. 



The valve is evidently that of an Estheria, much truncated 

 anteriorly, and w^ith the lines of growth much thicker, higher 

 and closer together than in any North American species known 

 to us, and may prove when better specimens are found, to be 

 allied to the tertiary Siberian E. middendorfii . 



The species is named in honor of the discoverer, J. W. Dawson, 

 LL.D., who has so persistently and ably investigated the Leda 

 clays of Canada. .1. >S'. Packard, jr. — (^From the American 

 Journal of Science.^ 



