676 UPPER MIOCENE VOLCANOES. [Oh. XXXI. 



which they belong reaches to the height of 1100 feet or more in the 

 interior, we conceive that an upheaval of at least that amount has 

 taken place. The Clypeaster alius, Spondylus gcederopus, Pectunculus 

 pilosus, Oardita calyculata, and several other shells, serve to identify 

 this formation with that of the Madeiras, and Ancillaria glandiformis, 

 which is not rare, and some other fossils, remind us of the faluns of 

 Touraine. 



The sixty-two Miocene species which I collected in the Grand 

 Canary are referred, by Dr. S. P. Woodward, to forty-seven genera, 

 ten of which are no longer represented in the neighboring sea, namely, 

 Corbis, an African form, Hinnites, now living in Oregon, Thecidium 

 (T. Mediterranean, identical with the Miocene fossil of St. Juvat, in 

 Brittany), Calyptrwa, Hipponyx, Nerita, Erato, Oliva, Ancillaria, and 

 Fasciolaria. 



These tuffs of the southern shores of the Grand Canary, containing 

 the Upper Miocene shells, appear to be about the same age as the 

 most ancient volcanic rocks of the island, composed of slaty diabase, 

 phonolite, and trachyte. Over the marine lavas and tuffs trachytic and 

 basaltic products of subaerial volcanic origin, between 4000 and 5000 

 feet in thickness, have been piled, the central parts of the Grand 

 Canary reaching the heights of about 6000 feet above the level of the 

 sea. Some lavas have a very fresh aspect, and have been poured out 

 since the time when the valleys were already excavated to within a 

 few feet of their present depth. They must be very modern, geo- 

 logically speaking, but being anterior to the European colonization of 

 the Grand Canary, their date is unknown. 



A raised beach occurs at San Catalina, about a quarter of a mile 

 north of Las Palmas, which is situated in the northeastern part of the 

 island. It intervenes between the base of the high cliff formed of the 

 tuffs with Miocene shells and the sea-shore. From this beach, elevated 

 twenty-five feet above high-water mark, and at a distance of about 150 

 feet from the shore, I obtained, with the assistance of Don Pedro 

 Maffiotte, more than fifty species of living marine shells. Many of 

 them, according to Dr. S. P. Woodward, are no longer inhabitants of 

 the contiguous sea, as, for example, Strombus bubonius, which is still 

 living on the West coast of Africa, and Cerithium procerum, found at 

 Mozambique : others are Mediterranean species, as Pecten Jacobceus 

 and P. polymorphic Some of these testacea, such as Cardita 

 squamosa, are inhabitants of deep water, and the deposit on the whole 

 seems to indicate a depth of water exceeding a hundred feet. 



Azores. — In the island of St. Mary's, one of the Azores, marine 

 fossil shells have long been known. They are found in the northeast 

 coast in a small projecting promontory called Ponta do Papagaio (or 

 Point-Parrot), chiefly in a limestone about 20 feet thick, which rests 

 upon, and is again covered by, basaltic lavas, scoriae, and conglom- 

 erates. The pebbles in the conglomerate are cemented together with 

 carbonate of lime. 



