90 Sketch of the Infusoria of the family Bacillaria. 



to redness, nor by action of hot hydrochloric acid. They fuse 

 with effervescence with carbonate of potassa, and the fused mass 

 when treated with hydrochloric acid gives silica in abundance. 

 There can, then, be no doubt that the glass-like filaments of this 

 species are siliceous. Our species agrees in all respects with au- 

 thentic European specimens (in Herb. Tor.) collected by Hoff- 

 man Bang, at Hofmansgave. 



2. Gaillonella auriclialcea. (PI. 2, fig. 4, 4 a ?) Corpuscles elon- 

 gated, cylindrical, truncate, flattened smooth, contiguous, a simple or 

 double pierced furrow in the middle of the body, ovaries greenish, be- 

 coming golden yellow when dry, y^^ line. Conferva orichalcea, Ag., 

 Syst. Alg. p. 86. Meloseira orichalcea, Ktz., Linn., 1833, p. 72, 588, 

 PI. 17, fig. 68. 



Onr species (PI. 2, fig. 4, a, b,) agrees so closely with Kutzing's 

 figure 68, even in the branching character and occasional produc- 

 tion of large globular joints, (see (c) in fig. 4,) that I feel little 

 hesitation in considering it as the G. mirichalcea, although I am 

 unable to perceive the "sillon perce" alluded to by Ehrenberg in 

 his specific character. This species might easily be mistaken for 

 a Conferva. It often forms bluish green masses, of full a foot in 

 extent, and while fresh it is quite as flexible as any Conferva ; 

 but on drying, it becomes of a light brassy yellow color, and is 

 then excessively fragile. There is much variation in the diame- 

 ter of the filaments, and in the relative length of the joints. The 

 filaments which have the smallest diameter, have, generally, the 

 longest joints. They retain their forms when heated to white- 

 ness, and when treated with strong nitric acid. This species oc- 

 curs in springs, rivulets, &c., and appears as common in this 

 country as in Europe, In (PL 2, fig. 4, b,) is represented a spe- 

 cies of Gaillonella apparently distinct from figs, 4 and 4 a. It 

 shows the pierced furrows and agrees in most respects with the 

 figure of G. aiirichalcea given by Ehrenberg in his memoir en- 

 titled Die Fossilen Iiifasorien und die lehendige Dammerde, PI. 

 1, fig. 23, It is possibly, only a state of our species above refer- 

 red to. It occurs in ponds near West Point. 



while the rocks below low water mark are covered with Balani and minute coral- 

 lines, and the marine flora is represented by vast qiiantiiies of a very elegant Poly- 

 siphonia, iiov. sp. ?) abundance of Enleromorpha intestinalis, Ectocarpus siliculosus, 

 and an elegant Alga, apparently identical wiili Delesscria Leprieurii of Montagne, 

 ■vviiich was first detected on the shores of Cayenne. (Sec Annales dcs Sciences 

 Naturelies, 2d series, Bot, torn. 13, p. 196, and pi. 5.) 



