AND PORTO SANTO. 11 



Nearly the same vegetation presented itself (the daphne gnidiuin 

 and euphorbia dendroides appearing to be the most plentiful), with 

 the addition of some beautiful little tufts of the anagallis cerulcea, 

 some large patches of the antirrhinum majiis, and a yellow variety 

 of the achillea nobilis. The formation, howevei-, was totally dif- 

 ferent to the three which were in view on the northern side of the 

 river, mz., the granite at Cintra, the transition Hmestone above 

 Ajuda, and the basalt, capping the hills between the aqueduct 

 and the city. It was a range of calcaire grassier, or coarse shelly 

 limestone, about 300 feet high, and extending northwards some 

 miles along the river. It was soft but firm, frequently very sandy, 

 sometimes of an orange yellow (especially within), but generally 

 of a greenish and yellomsh grey. Pebbles of silex were occa- 

 sionally imbedded, and more frequently in masses resembling clay: 

 it soiled the fingers, effervesced moderately, and seemed deposited 

 in deep, horizontal, beds more compact upwards. The shells 

 were so thickly imbedded, that whole masses appeared to be 

 exclusively composed of them. They were all marine (with the 

 exception of the bulimus decollatus), and comprehended three 

 species of ostrea (0. plicatida, O. edulis, and O. canalis), the 

 panopaa faujasii, the cyprina islandica, the pecten vulgare, and 

 p. saxatile\ with four species of terebratula, three of turritella, see 

 fig. 7 and 8, a cardita, a balanus, a nassa, a murex, a conus, with 

 one valve of a shell of considerable size, and of a bright orange 

 colour, fig. 2, which I do not recognise, and a smaller one of a 

 white colour, fig. 6, which cannot be referred either to tellina, 

 venus, or cytherea, but which resembles all of them'. The fiu:us 



'' Rumphius, Cabinet d'Amboine, pi. xliv. 



' The recent shells found among the rocks washed by the river, were the ostrea 

 plicatida, chama albida? anomia squamula, nassa communis, mytilus incurvatus, 

 cardium costatum, a venus, cytherea, meleagrina, several species of trochus, a murex, 

 patella, and immense masses of the balantts imperforatus. 



C 2 



