1846.] MORRIS AND SHARPE ON FALKLAND ISLANDS FOSSILS. 277 



The specimens examined of these three species of Spiiifer are 

 so imperfectly preserved, that it is impossible to obtain good specific 

 characters; they are however very distinct from each other; but it 

 may be stated that they also bear a general resemblance to the spe- 

 cies of Spirifer described in Count Strzelecki's work on Australia, and 

 a careful comparison might be hereafter advantageously instituted 

 with better-preserved specimens. 



The number of species collected by Mr. Darwin from the Falk- 

 land Islands is too limited to justify any close comparison with the 

 palasozoic fauna of other portions of the globe, still however their 

 allocation is rather interesting : of the eight species above described, 

 all belong to the family of Brachiopoda, which appear to have con- 

 stituted the chief portion of the fauna of that locality, and there is also 

 a species of Orbicula (V\. X. fig. 5), too imperfect to be described ; 

 these are associated with numerous traces of Crinoidal stems, an 

 Avicula, and fragments of a Trilobite. 



The individuals belonging to the various species of Spirifer were 

 few in number; those belonging to Orthis, Chotietes and Atrypa 

 appear to have been abundant or rather gregarious in character, 

 just as we find some species of Terebratulce at the present period 

 abounding on the sand and mud-banks beneath the sea. 



In their alaeform character and the paucity of ribs, the species of 

 Spirifer approach those obtained from the altered limestones and 

 sandstone of Southern Australia and Van Diemen's Land ; they like- 

 wise bear some resemblance to Devonian species from the Eifel, and 

 to some forms described by M. d'Orbigny from South America. 



The Orthidae, of which the individuals are numerous in the Falk- 

 land Islands, have not yet been observed in Australia, and are rarely 

 met with on the continent of South America : as regards their affi- 

 nity, they bear considerable resemblance to some species of the 

 northern regions which characterise the Lower Silurian strata, as 

 described in the 'Silurian System' of Sir R. Murchison. Thus we 

 cannot attempt to place the beds in the Falkland Islands which have 

 supplied these specimens, on the level of any particular portion of 

 the European scale of formations, but must be contented with saying 

 that they belong to a part of the palaeozoic series of which the posi- 

 tion is still undetermined. In the intermixture, abundance and 

 analogy of form of the species of Orthis, Atrypa and Chonetes, they 

 bear a still more remarkable resemblance to the collection made by 

 Captain Bayfield from North America. 



The Chonetes Falklandica, as previously observed, is scarcely 

 separable from C. sarcinulatay a species having a wide geographical 

 and vertical range. 



The general occurrence and extensive distribution of many species 

 of J3rachiopoda, either identical in character or analogous in form, in 

 the palaeozoic strata, has always been a subject deeply interesting to 

 the palaeontologist, and has given rise to the opinion, that a more 

 equable temperature, a greater uniformity of physical character and 

 surface arrangements may have been instrumental in producing this 



