PENGELLT— FOSSILS OF DEVOK AND COENWALL. 



17 



less varied, the fossils are frequently as numerous individually in 

 the slate as in the limestone. 



It must be understood that any one of the ten columns just noticed 

 shows, not the total number of species common to the areas the 

 initials of which stand at its head, but simply the number at once 

 common and restricted to them collectively ; thus the second of these 

 columns, headed L. S. D., L. C, shows that five species are common 

 and restricted to Lower South Devon and Lower Cornwall, but in 

 the third column w^e find one species common to them and also to 

 Lower ^forth Devon, in the fourth one common to them and to 

 Upper North Devon, and in the eighth one found in each of them 

 and also in Upper North Devon and Upper Cornwall ; hence there 

 are eight species common to the two areas instanced, five of which 

 are restricted to them collectively, and three not. The same expla- 

 nation applies to the other areas. The total number of species found 

 in any area will be ascertained by adding the figures in all the 

 columns marked "Peculiar to " and " Common to," at the heads of 

 which the initials of the area are found ; thus, for example, a total of 

 forty-seven species of Zoophyta occurs in Lower South Devon, of 

 which forty are not found elsewhere in Devon and Cornwall. More- 

 over, as the column marked "Species" shows that the two counties 

 have yielded fort^^-nine species belonging to this class, it is evident 

 that two of the total number have not been met with in Lower 

 South Devon ; and so on for the other classes and areas, as is shown 

 in the five columns headed " Totals," and distinguished by the initials 

 of the areas. Ranged according to their 'peculiar specific fossil 

 wealth the areas stand, in descending order, thus : — Lower South 

 Devon, Upper North Devon, Upper Cornwall, Lower Cornwall, and 

 Lower North Devon ; the order is the same when the total number 

 of species found in them is considered, with the single exception 

 that, in that case. Lower North Devon and Lower Cornwall are 

 equal. 



Of the three hundred and forty-seven species, sixty-seven are met 

 w^ith in various parts of continental Europe, and seven in North 

 America ; six of the latter being included in the European sixty-seven, 

 and one of the six is also found in New South Wales ; thus making 

 a total of sixty-eight species common to Devon and Cornwall and 

 districts beyond the British Isles.* 



Comparatively few of the Devonian fossils of Devon and Cornwall 

 appear to have been derived from the Silurian Eauna ; eight species 

 only — just enough to suggest a problem or two — are referable to 

 that earlier period ; namely, three Corals, two Brachiopods, two 

 Lamellibranchiates — one from each of the sections Monomyaria and 

 Dimyaria — and one Cephalopod. The three corals are Favosites fihrosa, 

 Emmonsia hemisplicerica, and Chonophyllmn perfoliatum. The first 

 has been found in Lower Silurian rocks at Landovery, in the upper 



* See in Tabk I. the columns headed Eu. (continental Europe), Eu. Am. (Europe 

 and America), Am. (America), Eu. Am. Au. (Europe, America, and Australia.) 

 YOL. y. D 



