418 



Messrs. Carpenter, Jeffreys, and Thomson [Nov. 18, 



which are common to Northern and Southern latitudes, and which in- 

 habit the same bathymetrical zone, the Northern are usually larger than 

 the Southern specimens. It may perhaps be a not unfair inference that 

 the origin of such species is Northern, and that they dwindle and become 

 depauperated in proportion to the distance to which they have migrated 

 or been transported from their ancestral homes. 



32. The next week was occupied in sounding and dredging off Yalentia 

 and on the way to Gal way, at depths varying from 85 to 808 fathoms (Stations 

 2 to 7). The Fauna throughout was Northern ; and several interesting acqui- 

 sitions were made in all departments of the Invertebrata. Among these 

 may be mentioned : — Mollusc A: Nucula pumila (Norway), Leda friyida 

 (Spitzbergen and Finmark), Verticordia abijssicola (Finmark), Siphonoden- 

 talium quinquangulare (Norway and Mediterranean), and an undescribed 

 species of Fusus, allied to F. Sabini. — Echinodermata: the remark- 

 able JBrisinga endecacne?nos, hitherto only known as a Northern form. — 

 Actinozoa : Flabellum laciniatum, Edw. and J. Haime= Ulocyathus arc- 

 ticus, Sars (Norway and Shetland, as well as a Sicilian fossil), of which rare 

 and delicate coral unusually perfect specimens were obtained. That fine 

 Shetland Sponge Phakellia ventilabrnm was also met with thus far south, 

 in 90 fathoms. Many of the most marked types of the deep-water Crus- 

 tacea of the Shetland sea were here dredged ; while in company with 

 these were Gonoplax rhombo'ides, Fab., a well-known Mediterranean species, 

 an undescribed and very fine Ebalia, a new species of the Mediterranean 

 genus Fthusa, together with numerous Mysidea, Cnmacea, and Amphipoda 

 new to our Fauna. Cyprinididce also were abundant on this ground. 

 The 808 fathoms' dredging was then a novelty, being (as we believed) 

 the greatest depth ever explored in that way. The length of rope 

 paid out was 1110 fathoms, and the time occupied in hauling in was 

 fifty-five minutes. The same proportionate time was observed in other 

 dredgings during this cruise, viz. five minutes for every 100 fathoms of 

 rope. The dredge contained about two hundredweight of soft and sticky 

 mud, in appearance resembling " China clay." The animals brought up 

 on this occasion were quite lively. More than one specimen was exa- 

 mined of a small Gastropod (described and figured by Mr. Jeffreys as 

 Lacuna tenella), which had very conspicuous eyes. There was also a young 

 and active specimen of the large Norwegian Crab, Geryon tridens, Kroyer, 

 which is very rare in the Scandinavian seas, and was the only North 

 European Brachyuran which had not as yet been found in British waters. 

 — \Ve had here, for the first time, an opportunity of comparing the tem- 

 peratures indicated by Dr. Miller's "protected" Thermometers, and those 

 of the ordinary construction, at a considerable depth. The minimum re- 

 corded by one of the former was 41°-4, whilst that recorded by one of the 

 best ordinary thermometers was 45°*2. As this difference of 3°'8 was 

 almost exactly what the results of the experiments previously made had 

 indicated as the effect of a pressure amounting to one ton on the square inch 



