Mr. J. Gwyn Jeffreys on Dredging among the Shetland Isles. 247 



Journal,' ser. 2. vol. xxxiii. p. 130, expresses the views advocated 

 herein. The following is an extract therefrom : — 



" This is the classification which the writer of the criticism main- 

 tains should be sustained ; and we cannot see any reasonable objection 

 to it. It is perfectly just towards both M'Coy and D'Orbigny. It 

 infl^icts no injustice on any other author. It is not inconsistent with 

 purity of zoological nomenclature, or in any way injurious to science. 

 It does not require any modification in either of the original defini- 

 tions. The typical species are central and dominant forms of two 

 different groups of species which together form one larger general 

 group. Athyris, under this arrangement, is the generic name of 

 that group which has A. tumida for its type. Spirigera is a per- 

 fectly unexceptionable name for the other group, of which the typi- 

 cal form is S. concentrica. Prof. Hall's proposed genus Meristella 

 is precisely identical with the genus Athyris in its restricted sense 

 (as above explained), and cannot be admitted until some good reason 

 is shown for setting aside Davidson's arrangement. It belongs to 

 Prof. Hall to place this reason before the public in a clear and un- 

 sophisticated manner. If he succeed in maintaining his point, then 

 he will establish a classification for this group of fossils far inferior 

 to that proposed by Davidson. Spirigei'a must be suppressed, and 

 Athyris must take its place, and thus stand as the generic appella- 

 tion of a group of fossils for which it is not appropriate. We hold 

 that this change is not necessary ; and as it would, if adopted, be 

 injurious to science by affecting the purity of zoological nomenclature, 

 it cannot be maintained." 



XXX. — Fourth Report on Dredging among the Shetland Isles. 

 By J. Gwyn Jeffreys, F.R.S.* 



In spite of the weather (which was worse than usual in this 

 stormy region), some additional results of no slight interest 

 were obtained. The three requisites of such enterprises (time, 

 money, and experience) were not wanting ; and the valuable co- 

 operation of Mr. Norman, Mr. Waller, and Mr. Dodd, aided by 

 a good yacht and crew, and by a large stock of apparatus, left 

 nothing to desii'c except calmer seas. Dr. Edmonston and his 

 family again did all in their power to promote our endeavours ; 

 and Mr. Cheyne of Edinburgh kindly placed his house at Tan- 

 wick at our disposal. 



Discoveries in natural history are of several kinds, all of which 

 are nearly equally important : — 1. New species or forms. 2. Geo- 

 graphical distribution. 3. Habits of animals, including in the 

 present case those supposed to be dependent on the depth of 

 water. 4. Geological relations. 5. Extraneous incidents. 



* Communicated by the author, having been read at the Meeting of the 

 British Association at Dundee, 5th Sept., 1867- 



