On Some Carboniferous Entomostraca from Nova Scotia. 361 



invariably found in deposits tliat appear to have originated in the 

 shallow water to be found in estuaries, off" low coast-margins, or 

 where land or mud-flats were near, to account for the fragments 

 of wood, branches of Lepidodendron, and the fronds and stems of 

 Ferns that are so often found imbedded with this Entomostracan. 



With the remains of these littoral, estuarine, or shallow-water- 

 loving Entomostracans in similar Carboniferous deposits on each 

 side of the North Atlantic, it seems reasonable to assume that, 

 whether the migration has been from east to west, or from west to 

 east, it must have been through regions where shallow- water con- 

 ditions prevailed suitable to their existence. Whether such condi- 

 tions obtained in the Carboniferous period across any portion of the 

 area of what is now the North Atlantic,— or whether the migration 

 took place by a route that is now occupied by the continental areas 

 of Europe, Asia, and North America — there is scarcely evidence to 

 decide. There is much difficulty, whichever way we look at it ; and 

 it must suffice for us to have pointed out the fact that some of the 

 most common and characteristic of what have evidently been shallow- 

 water Entomostraca of the British Carboniferous strata are found 

 abundantly in equivalent rocks in Nova Scotia, as well as on this 

 side of the ocean. 



8. — Candona ? ELONGATA, sp. nov. Plate XII. Fig. 10. 



From the same shale as that in which the Carhonice occur, we have 

 a single valve that has much the character of the recent genus 

 Candona (ex. C. Candida). It may be briefly described as follows : — 



Elongate ; ventral margin slightly concave, dorsal margin curving 

 gently upwards to point of greatest width (or height), which is about 

 a fourth of the length from the hinder end ; posterior extremity 

 wider than the anterior. Surface smooth. Length -^ih. of an inch ; 

 greatest breadth -gVth of an inch. 



This species — so far as it is known from this single valve — has 

 some resemblance to Garhonia ? bairdioides, J. and K. ; but it 

 approaches much nearer to a large Candona that we have from the 

 Coal-measures of England, which was collected by the late Mr. W. 

 Molyneux, F.G.S., from the shales of the North-Staff"ordshire Coal- 

 field. 



Cythere? spp. indett, Plate XII. Figs. 11 a-c. 

 Cythere, Dawson, in part, Acadian Geology, 1868, p. 256, fig. 78a. 



Figs. 11 a, b, c, represent some single valves of probably two 

 species of Cythere ?, that are found associated with Leperditia and 

 BeyricJiia, in the Lower Coal-measures of Horton. The outlines 

 remind us of Carbonia pungens, J. and K., or of dwarfed specimens 

 of Cythere csqualis, J. and K. ; indeed, it is hard to say what known 

 form they resemble. We figure the specimens to draw attention to 

 them, and in the hope that better examples may turn up to allow 

 of their affinities being spoken of with more precision. 



9. — EsTHERiA Dawsoni, Joncs. Plate XII. Fig. 12. 

 Esiheria, Dawson, Acadian Geology, 1868, p. 256, f. IM. 



Mtheria JJawsoni, Jones, 1870, Geol. Mag. Vol. VII. p. 220, PI. IX. Fig. 15; 

 and Dec. II. Vol. II. 1878, p. 101, PI. III. Fig. 2. 



