OF LABRADOR AND MAINE. 245 



and broken in the least. In the Saco beds, and in other beds generally, some forms of 

 Serripes grbnlandicus are much flattened and slightly elongated, differing in this respect 

 greatly from the recent specimens, but all the changes of form evidently took place after 

 the death of the animal. The mammalian remains occurred in the upper part of this series 

 of beds. The bison teeth were taken out by Sir Charles Lyell about fifteen feet from the 

 surface. Throughout the beds occurred in abundance concretions of clay, easily crumbling, 

 which assumed cylindrical or spherical forms upon being hardened by exposure to the air. 

 These have already been noticed by authors. They are evidently concretions around the 

 fronds of Algre and animal remains. They are very plentiful, and have been observed in 

 abundance only in beds of this horizon. 



These beds of clay become more sandy as they reach the top of the deposit, until the 

 beds graduate into a loamy, sandy clay, affording our best arable soil. All these beds, 

 with the exception of the lowest gravelly strata graduate into each other. 



5. Eesting unconformably upon them is a thick bed of marine coarse gravel or shingle, 

 which evidently once formed a continuous sheet of sand, — an ancient sea-beach, and is 

 now mostly rearranged (6) into river terraces. 



Total thickness of the entire formation, about one hundred and thirty feet. 



The clay beds containing the fossils enumerated below are gently inclined toward the 

 east, dipping at an angle of about 10° toward the present bed of the river. 



Lepralia hjalina Linn. On Serripes gronlandicus. 



Lepralia variolosa Johnst. Several patches in shells of Buccinum. 



Membranipora americana D'Orb. Occurred on Pholas crispata. 



Pecten islandicus Linn. Large and coarsely ribbed ; not very abundant. 



Leda buccata Steenstp. (X. Jacksoni Gould.) Of the typical form. 



Nucula antiqua Mighl. Very abundant, and finely preserved, the greenish brown epider- 

 mis preserving its original hue and lustre. Some very large and flattened forms occurred 

 with those much elongated and much shorter from beak to lower border than in the typ- 

 ical, ventricose form. 



Mytilus edulis Linn. The common form, young and old, were very abundant, and also the 

 variety pellucidus. 



Mytilus discrepant. (3fodiolaria nigra Gray.) A few valves. 



Astarte compressa Linn. (A. clliptica Gould.) Abundant, but not so common as the forms 

 of A. Banksii. 



Astarte Banksii Leach. (A. Richardsoni Reeve.) Common. The fossil forms agree pre- 

 cisely with those living, which I have dredged abundantly in Labrador. 



Serripes gronlandicus Beck. Common. 



Cardium pinnulatum Conr. Frequent. 



Pandorina arenosa Sacchi. A few valves. 



Mya arenaria Linn. Very abundant. 



Pholas crispata Linn. One valve larger than common in recent forms. 



Natica clausa Brod. et Sowb. Some specimens were greatly flattened, the spire appear- 

 ing as if driven in to the body of the shell. 



Buccinum gronlandicum Hancock. This species occurred in a broken and generally imper- 

 fect state. Some were large and the waves very much developed. Others occurred 

 smaller, with the outer layer of shell off, corresponding with forms from Portland and 

 Augusta, and agreeing well with the characteristic drawing in Lyell's paper on the fossil 

 discovered at Quebec by Capt. Bayfield (Trans. Geol. Society, vol. vl 1S42, p. 135). 



