1872.] 



' Shearwater ' Scientific Researches. 



587 



Part IV. 



Biological Researches :n the Mediterranean. 



79. The Dredgings which we carried on upon the Adventure and Skerki 

 Banks, between Sicily and the Coast of Africa, chiefly at depths between 100 

 and 200 fathoms, did not add any thing of importance to the collection 

 which we made in the previous year in the same locality, save some Sponges 

 of considerable interest. We were struck with the limitation of the areas to 

 which particular types appeared restricted ; for when encouraged by " a 

 good haul " to put down the dredge a second time in the same locality, it 

 frequently came up again almost empty. "Whether this depended on a slight 

 change of depth, or on the direction of under-currents, which probably have 

 a considerable influence on these shallows, it is impossible to say. This 

 fact, however, seemed constant, — that below 150 fathoms Animal life was 

 extremely scanty ; whilst even down to that depth Nullipores were often 

 very abundant, the dredge coming up full of them. As there is no doubt 

 of the Vegetable character of Nullipora, I deem this fact of considerable 

 significance, as indicating that Light must penetrate to that depth in suffi- 

 cient amount to enable this plant to decompose carbonic acid. — Our 

 Dredgings along the African shore, though by no means unproductive, 

 did not furnish any specimens of novel interest. Mr. Gwyn Jeffreys has 

 kindly supplied me with the following List of the more remarkable shells 

 obtained along the Tripoli Coast : — 



Brachiopoda. Platydia anomio'ides, Scacchi. 



Conch ifera. Pleuronectia fenestrata, Forbes: Leda pygmcea, v. Mini- 

 ster : Area obliqua, Philippi : Lepton nitidum, Turton : L. sulcatulum, 

 Jeffreys: Kellial cycladia, S.Wood: Axinus transversus*, Bronn : 

 Astarte sulcata, Da Costa ; var. elliptica, Brown : A. triangularis, 

 Montagu ; and var. margine integro : Crassatella planata*, Calcara, 

 = Gouldia modesta, H. Adams : Venus effossa, Bivona : Pecchiolia granu- 

 lata*, Seguenza. 



Solenoconchia. Cadulus subfusiformis, Sars. 



Gastropoda. Scissurella crispata, Fleming : Rissoa cimico'ides, Forb. : 

 R. subsoluta, Aradas : R. Stefanisi, Jeffr. : Odostomia unifasciata, 

 Forb.: O. minuta, A.Adams: Mesalia pusilla, Jeffr.: Cerithiopsis 

 Metaxa, Delle Chiaje : Natica fulminea, Risso : Solarium discus*. Ph. : 

 S. Architce, Costa : Trophon vaginatus, Jan : Pseudomurex lamellosus, 

 Jan: Nassa limata, Chemnitz ; var. nana-i Pleurotoma torquata* \ 

 P. Renieri*, Sc.: P. hystrix*, Jan: Columbella haliceeti, Jeffr.: Vo- 

 luta pumilio, Brusina (the Marquis de Monterosato has rightly deter- 

 mined this to be the very young of Cyprcea lurida ; the first whorls are 

 exquisitely reticulated, as in Befrancia) : Actceon pusillus, Forb. 



Of these, the species marked * are especially interesting, because until 

 lately they were known as fossil only. 



