XV 



and of working down to greater depths. His inquiries early led him 

 to suspect that the marine Molluscan Fauna of the present time is the 

 direct continuation of that of the later Crag period ; and this idea 

 received strong confirmation from his finding many Crag shells, sup- 

 posed to have become extinct, still living in the seas around Shetland 

 and the Hebrides. 



After having published, from time to time, numerous short papers 

 on the results of his explorations, Gwyn Jeffreys determined to bring 

 out a systematic treatise on British Conchology, not in rivalry with 

 the elaborate work of Forbes and Hanley, but on a less costly scale, 

 generic types only (instead of specific) being illustrated. The first 

 volume of this treatise appeared in 1862, and the fifth and last in 

 1869. He had previously removed from Swansea to London ; having 

 been called to the Bar in 1856, with the view of practising in the 

 Court of Chancery and before Parliamentary Committees. In 1866, 

 however, he retired altogether from legal practice, with the view of 

 devoting his whole time to scientific work, and soon afterwards trans- 

 ferred his residence to Ware Priory, Herts. There, whilst taking an 

 active interest in the business of the county (of which he became 

 J.P., then D.L., and in 1877 High Sheriff), he continued his concho- 

 logical studies ; and, with his estimable and accomplished wife, gave 

 a hospitable reception to his numerous scientific friends of all 

 countries. 



Gwyn Jeffreys's dredgings, having been hitherto prosecuted on 

 what is now regarded as the submerged portion of the Continental 

 platform, had not been carried deeper than 200 fathoms. But 

 the feasibility of exploring much greater depths having been 

 demonstrated in the experimental cruise of the " Lightning " in 1868 

 (when a successful haul was brought up from 650 fathoms), the 

 " Porcupine " Expedition was next year fitted out expressly for the 

 prosecution of still deeper explorations. As both Dr. Carpenter and 

 Professor Wyville Thomson — who had been the joint promoters of 

 this research — were precluded by their official duties from taking 

 charge of the work during the earlier part of the season, they were 

 very glad to avail themselves of Gwyn Jeffreys's offer to superintend 

 it ; and the results proved in every way satisfactory. During the first 

 cruise the dredge was successfully worked at the then unapproached 

 depth of 1476 fathoms, thus preparing the way for the great exploit 

 of the expedition, the 2435 fathoms' dredging in the second cruise. 

 Gwyn Jeffreys's Report of the First Cruise ("Proc. Roy. Soc," Nov. 18, 

 1869, vol. 18, pp. 415 — 423) mentions, among the most remarkable 

 novelties of his deepest dredgings, the singular Clypeastroid, now 

 known as Pourtalesia Jeffrey si* and the beautiful little Orbitolite 



* When this was first brought up, it was supposed to be an entirely new form. 

 On the return of the Expedition, however, Professor Wyville Thomson learned that 



