52 DREDGING EXPEDITION. 



explanation of the exposed lens of the cephalopod ; he 

 controverted Owen's opinion as to the eye of the 

 animal possessing a perforated cornea and an aqueous 

 chamber, and held by Cuvier's description of the 

 organs. In reference to the second peculiarity, or the 

 glandular body or mass, which Owen and Cuvier had 

 viewed as a cushion to guard the optic ganglia from 

 pressure, Mr. Ooodsir considered it an organ which had 

 already performed its functions in the embryo, and 

 analogous to the choroid gland of fishes. 



In June 1839, Goodsir and Forbes made an 

 excursion to Shetland and Orkney, where they spent a 

 fortnight in dredging. They were not so successful in 

 their search for air-breathing gasteropods as in other 

 directions, wherein they discovered new animals, and 

 had the opportunity of supplementing the descriptions 

 given by naturalists of some of the rarer species 

 belonging to each locality. The results of this 

 dredging expedition were laid before the Fife societies, 

 and afterwards communicated to the British Associa- 

 tion. Amongst the numerous specimens they obtained 

 was a zoophyte, the largest known form of its tribe, 

 about four inches long, and with a stem half-an-inch 

 in diameter. They obtained it in considerable num- 

 bers on a sandy bottom, in about 10 fathoms of 

 water, at Stromness, Orkney, and supposing it to be 

 an undescribed form, proposed to give it the name 

 EUisiaJios maris; but, to their disappointment, found 

 that it had been discovered a short time previously 

 by the Norwegian naturalist Sars, and named Cory- 



