1870.] 



Deep-sea Researches. 



175 



times that of the Baltic towards the German Ocean (§ 123) ; and we would 

 suggest whether it might not be possible, through our Consulate (which 

 has an office at the Goletta), to have a regular series of observations made 

 upon the relative densities of the water of the lake and that of the sea, and 

 upon the direction of the upper and under current in the channel of com- 

 munication between them, that might furnish valuable data for the com- 

 plete elucidation of the subject of currents occasioned by excess of evapo- 

 ration. We availed ourselves of this short rest to visit the town of Tunis, 

 which, for the most part, retains its genuine Moorish characters ; as well as 

 the ruins of Carthage, a few miles off, the most remarkable part of which 

 consists of a series of immense reservoirs for water, supplied by an aque- 

 duct that brought it from a range of mountains at no great distance, 

 from which also the modern town of Tunis is supplied. 



55. Quitting Tunis at mid-day on Tuesday Sept. 6, we resumed our 

 Dredging-explorations on more productive ground, — the shallow between 

 the Eastern and Western basins of the Mediterranean, that extends between 

 the African coast and Sicily, and is termed the "Adventure Bank," from 

 having been first discovered by Admiral Smyth when surveying in H.M.S. 

 * Adventure.' The depths here range from about 30 to 250 fathoms. 

 When passing Cape Bon, we fell in with another small fleet of Italian Coral- 

 fishers ; and were surprised at the large outlay incurred for such small re- 

 turns as they seemed to be obtaining. We here found, between 25 and 

 85 fathoms, the following species of Mollusc a: Trochus suturalis, Ph. 

 (Sic. foss.) ; Xenophora crispa, Konig (Sic. foss.) ; Cylichna striatula, 

 Forb. (Sic. foss.) ; C. ovulata, Brocchi (Sic. foss.). And seven miles off 

 the point called Rinaldo's Chair, between 60 and 160 fathoms, we obtained 

 Tellina compressa, Brocchi (Sic. foss.), a species possessing the following 

 synonyms — Tellina striatula, Calcara ; T. strigilata, Ph. ; Psammobia 

 Weinkauffi, Crosse ; and Angulus Macandrei, Sowerby : also an interesting 

 Annelid, Praxilla prcetermissa, Malmgren (northern). Here, again, we 

 brought up a great abundance of Polyzoa ; and many of these have proved 

 of great interest. One, in particular, of a beautiful, very open reticular plan 

 of growth, is the type of a new genus, of which another species had been 

 previously obtained by Mr. Busk from the Canary Islands, and which he will 

 describe under the name of Climacopora. Many of the species obtained had 

 been previously known only as Tertiary Fossils. A complete account of them 

 will be published by Mr. Busk hereafter. Abundance of Shells were here 

 found ; among them we obtained a considerable number of living specimens 

 of Megerlia truncata, including a whole series in various stages of growth, the 

 youngest of which presented a very remarkable character, — a set of setce pro- 

 jecting from the margin of the shell, the length of which exceeded its own 

 long diameter. Among other species of interest were : — Kellia, sp. n. (Sic. 

 foss.); Gadinia excentrica, Tiberi; Rissoa, sp. n. ; Scalaria frondosa> J. Sow. 

 (Sic.&Cor.Cr.foss.) ; Odostomia unifasciata, Forbes; Pyramidella plicosa, 

 Bronn (Sic. & Cor. Cr. foss.)=P. Iceviuscula, S. Wood ; and Actccon pu- 



