Zoophyta. 



237 



to this species. Fig. 46 is a smaller species ; differing very deci- 

 dedly from the first, but very rarely met with. Fig. 44 is still 

 smaller ; the scales being minute, and I have found only one speci- 

 men of it. The fish in this case, as may be seen by the drawing, 

 appears not to have lain upon its side, as they generally do, when it 

 was enveloped in the rock. There is occasionally found a specimen 

 of greater length than any which are sketched ; and yet the scales 

 are smaller than those on fig. 45 : I suspect this to be a fourth spe- 

 cies : but I have no specimen sufficiently perfect to permit a drawing 

 to be taken. 



Mollusca. 



The only molluscous animal which I have detected in the new red 

 sandstone formation, was found in rolled masses in Amherst : and 

 the only specimen at all distinct, is sketched on Plate XL Fig. 17; 

 and belongs to the College collection in that place. Although much 

 broken, there can be little doubt but it is an orthocera. For a long 

 time I supposed the rock containing this mould, was a wacke-like 

 trap : but I am now satisfied that it is a micaceous sandstone, more 

 indurated than is common. I should not be surprised if it should 

 hereafter appear, that the vicinity of Turner's Falls is the spot from 

 which this specimen originated. 



At those falls I obtained the specimen No. 282, on whose surface 

 are some protuberances that much resemble a univalve shell : but 

 they may be concretions. 



Zoophyta. 



Under this head I introduce a remarkable organic relic, which I 

 recently discovered on the brown shale, or rather fine micaceous 

 sandstone, on the banks of Westfield river, (generally called Agawam 

 river near its mouth,) in West Springfield. It is characterised by 

 grooves and correspondent ridges, which sometimes ramify, and by 

 small somewhat polygonal reticulations, which cover the entire sur- 

 face of the shale as far as the grooves extend. (Nos. 264, 265.) 

 These reticulations are rarely more than one quarter of an inch in 

 diameter, and they diminish in size as we approach one extremity of 

 the impression. No animal or vegetable matter remains upon the 

 shale, yet the grooves and the reticulations are quite distinct. Plate 

 XIII. Figs. 34 and 35, are sketches of this organic impression ; the 

 latter showing the diminution in size of the net work, towards one 



