1858.] GEMMELLARO — SICILY. 507 



sides fragments of the same calcareo-siliceous deposit, but less exten- 

 sive. On the east side there is one patch entirely isolated, which, 

 after great labour, I reached, up the perpendicular ascent of the 

 decomposed rock. I measured the height, which is 1 1 metres 1 

 decimetre above the water. This fragment (lembo), which marks 

 one of the greatest heights in our coast above the sea in the present 

 epoch, is isolated on the side of the basalt ; perhaps because the rock, 

 having fallen into fragments, may have carried with it the lower part, 

 which was its base. The basalt presents no lithophagous shells in 

 its structure ; but corrosion is seen at some points, which depends, 

 in my opinion, on the action of external agents, and chiefly those of 

 the salts of sea-water, which continually tend to bring it down. 



The Pialsagia and the Faraglione del Mezio have also on their 

 weathered sides patches and fragments of the same nature ; and to 

 the west of this last such patches are at considerable heights, and in 

 the zone of the Modiola lithophaga, Lamk. ; here we see adhering 

 a very large Spondylus gcederopus. 



The Faraglione grande at a certain height, in consequence of the 

 continual giving way of its prisms, presents nothing of interest to 

 the observer ; whilst in the lower part we find patches of the usual 

 calcareous deposit 4 to 6 metres above the sea. 



In the island we find interesting phenomena. On its sides are 

 many fragments of the calcareo-siliceous shelly deposit more or less 

 high above the level of the sea ; here the argiliolite and there the 

 basalt show a zone of irregular corrosion some metres from the water. 

 The island has large clefts, almost all directed from north to south. 

 In the most western of these, on the sides, are great quantities of 

 patches of calcareo-siliceous deposits, similar to those which are seen 

 on the flanks of the other basaltic rocks, extending from the level of 

 the sea to the height of 7 metres 8 decimetres, the maximum. These 

 patches are horizontally bored by the Modiola lithophaga, Lamk., 

 which is found in all periods of its organic development ; and we also 

 find great part of the littoral shells now living on the coast. The 

 argiliolite, which forms the sides of this cleft above the before-men- 

 tioned patches, is also bored for about 5 more metres by the Modiola 

 lithophaga, Lamk. ; so that we have at this point one side bored by 

 lithophagous shells, as high as almost 13 metres above the sea. 



In the great eastern cleft we find a marine breccia, formed of blocks 

 of augitic lava, basalt, and argiliolite, at the height of from 4 to 6 

 metres. In it there are great quantities of shells, which are in a fine 

 state of preservation ; among these many are adhering to the breccia 

 in a normal position. 



Of these, the following species are identical with those now living 

 on our shores : — Area Noce, L., Cardita calyculata, Lamk., Patella 

 ccerulea, Lamk., Fissurella gibba, Phil., Monodonta corallina, L., 

 Buccinum variabile, Phil., Rissoa calathisca, Trochus cingulatus, 

 Brocchi, T. Adansonii, Payr., Mitra lutescens, Lamk., Colombella 

 rustica, L., Turbo neritoides, L., Cyprcea lurida, L., Vermetus 

 gig as, Biv., and others. 



The lateral walls of these clefts are bored by Modiola lithophaga 



VOL. XIV. PART I. 2l 



