398 BOARD OF AGRICULTURE. 



Navicula vhomboidcs and Sporangium. C3'mbella cuspidata. 



Navicula rhynchoccphala. Surirella biseriata. 



Pinnularia nobilis. Tabellaria flocculosa. 



Pinnularia major. Cyclotella Kutzingtana. (Rare.) 



Pinnularia Tabellaria. Odontidiura. (Large.) 



Pinnularia Stauroneiformis. Odontidium Tabellaria or 



Stauroncis Bailcyi. Fragilaria undata. 



Stauronois pluvniccnteron. Encyoncma? 

 Gomphonema acuminatum. 



Ill acUlitiou to the above a number of other species occur, but not 

 in ci condition to be satisfactorily determined. Among these I may 

 enumerate Navicula offinis, ? two varieties of Nitschia, (one of wliich 

 I suppose to be identical with a similar form detected by A. M. 

 Edwards, Esq., of New York, in a deposit from Bemis lake, N. H., 

 the other undescribed,) and some curious varieties of the genus 

 Himantidium. One of the latter is about as long as II. areas, but 

 with an undulate outline swelling in the centre of the dorsal region 

 into a rounded cone, and also enlarged at the extremities which 

 turn upwards. Only a single pustule was detected. The varieties 

 of this genus occurring here are very numerous and interesting, 

 especially those of " II. undulatum." I shall endeavor to speak 

 more fully of these and other doubtful forms upon some other oc- 

 casion, such descriptions being out of place here. 



Tlic deposit at Adley pond, Phillips, is much less pure than the 

 preceding, containing numerous pieces of sharp quartzose sand. 

 It is more like the common sub-peat deposits of the eastern States 

 than the above. It contains the usual variety of species, less in 

 number, however, than those above enumerated. It is especially 

 marked by great variety in the genus Eunotia, which is Cf)mpara- 

 tively rare in the Beddington earth. Adley pond is, I believe 25 

 acres in extent, the deposit cropping out upon its edge. 



The Brownfield earth is quite impure and not particular]}^ inter- 

 esting. It is from below peat, and is apparently in a state of de- 

 composition, many of the forms being fragmentary. The earth from 

 a pond in Calais is still less interesting. It consists of indurated 

 lumps, often stained with iron, (^uite impure, and the forms much 

 broken. 



Of the Bangor earth I know nothing, except that such a deposit 

 exists in that vicinity. It has been supposed to contain copper.* 



* Mr. A. E. Vcrrill of Cambridge, states that upon the south side of Clialk pond 

 in Watcrfocd, there is another of these deposits a foot thick. C. H. H. 



