78 Mr. Lyell on a recent Formation of 



of the lakes are rendered peculiarly enticing to herbivorous animals ; since 

 when the country is buried under snow, the aquatic grasses in such situations 

 continue for a long time to present a green surface*. 



Crustacea. — The Cypris ornata (Lamarck) occurs in the limestone, and is 

 the only crustaceous animal that the marly deposits of the Bakie have yet af- 

 forded me. The valves only remain ; and these, which are semi-calcareous 

 in the living animal, in the marl occur completely fossilized, like the stems of 

 CharaB which accompany them. This Cypris is not uncommon in the lakes 

 and ponds of England. Another species, the Cypris Faha, is mentioned by 

 Monsieur Brongniart as occurring in an ancient freshwater formation in the 

 department of the AUier, in the south-east of France. (Oss. Foss. 2d edit, 

 torn. ii. p. 536.) 



Testacea. — The following shells are not uncommon in the limestone or 

 rock-marl, and belong (particularly the three first) to the same species which 

 are most abundant in the shell-marl of Forfarshire. 



Names of Montagu. Names of Lamarck. 



1. Helix peregra Limnea peregra. 



2. Turbo fontinalis Valvata fontinalis. 



3. Cardium lacustre Cyclas lacustris. 



4. Helix contorta Planorbis contortus. 



5. Patella lacustris Ancylus lacustris. 



Many of these shells are very minute, and must have belonged to very young 

 individuals : indeed we rarely meet with full-grown shells in the marl of 

 this country. The shells in the limestone are sometimes empty, but are ge- 

 nerally filled with the substance of the matrix, and when taken out, leave a 

 smooth polished mould, as in the older limestones. Sometimes the shells con- 

 tain crystals of carbonate of lime. 



* It is probably in the sites of ancient lakes that the remains of the Irish elk are found, both 

 in Ireland and in that part of the Isle of Man called the Curragh ; since they occur in beds of marl 

 covered by peat. The author of the article on Organic Remains in the Edinburgh Encyclopedia^ 

 states that in the Curragh the elks lie within a small space, as if assembled in a herd ; that their 

 skeletons are generally entire, in an erect position, and (as the people of the country who dig 

 them out affirm) having the nose elevated as high as possible. The position of the skeletons is the 

 same that we should expect to observe in animals which had sunk in boggy ground, endeavouring 

 to keep the nose aloft as long as possible. Cattle which have thus sunk in the bogs of Forfarshire 

 are said to be laired, from the old verb lair, to mire. The skeletons of the great mastodon found 

 in boggy gound near the great Osage river in Louisiana are found in a vertical position, as if they 

 had sunk in the bog [Cuvier, Oss. Foss. 2d edit. tom. i. p. 222]. And a skeleton of the same 

 animal lately discovered in New Jersey, about 40 miles to the south of New York, was found in 

 the same position in a stratum of black earth, the head being on a level with the surface. [Ann. 

 of Lye. New York, vol. i. p. 143.] 



