258 



REPORT 1868. 



Microciona Isevis, Sow. 



ambigua, Sow. 



simplicissima, Sow. 



Hymeraphia vermiculata, Sow. 



coronula, Soiv. 



Hymedesmia- radiata, Sow. 



Zetlandica, Sow. 



occulta, Sow. 



Hymeniacidon reticulatus, Sow. 



perarmatus, Sow. 



membrana, Sow. 



paupertas, Sow. 



Halicnondria forcipis, Sow. 



simplex, Sow. 



scandens, Sow. 



? Halichondria Batei, Sow. 



albula, Sow. 



inornata, Sow. 



nmtulus, Sow. 



falcula, Sow. 



Isodictya varians, Sow. 



jugosa, Sow. 



Barleei, Sow. 



fimbriata, Sow. 



Raphioderma coacervata, Sotv. 

 Oceanapia Jeffreys!! (Sow.}. 

 Desmacidon Peachii, Sow. 



constrictus, Sow. 



Diplodemia vesicula, Sow. 

 Verongia Zetlandica, Soiv. 



VI. 



Mediterranean Species which occur in Shetland, but have not been found at 

 intermediate localities. . 



Two large and conspicuous animals, Portunus tuberculatus, Roux, and 

 Spatangus meridionalis, Risso, have been found abundantly in these dredgings 

 at a depth from eighty to one hundred and forty fathoms. They are well 

 known in the south of Europe, but were supposed up to the time of their 

 discovery in Shetland not to occur north of the Mediterranean. It is not 

 unlikely that Pagurus tricarinatus, Norman, will also prove to be a deep- 

 water Mediterranean form. All deep-water dredging seems to establish this 

 fact more clearly, that deep-water species have a much more extended geo- 

 graphical range than shallow- water and littoral forms. These Mediterranean 

 species must have made their way northwards in the abyss of the sea round 

 the western coast of Ireland, in which locality they will doubtless at some 

 future day be found. The classes on which it is my lot to report have been 

 so much neglected, and our knowledge therefore of their distribution is at 

 present so extremely limited, that it is at present impossible to draw any 

 satisfactory conclusions as to their range ; but I feel satisfied that when 

 hereafter fuller and more accurate investigation shall have been carried on 

 both in the Mediterranean and our own coasts, not only will the number of 

 species common to the two extremities of Europe be found to be much greater 

 than is now generally supposed, but also that a very large proportion of such 

 species will prove to be forms which will be met with in the depths of the 

 Mediterranean and of the seas to the west and north of our country, but 

 which will be found to be absent from the channels which intersect and the 

 shallower water which immediately surrounds our islands. Meanwhile the 

 occurrence of Portunus tuberculatus and Spatangus meridionalis is of excessive 

 interest, as such fine and handsome species could not have been well over- 

 looked, or have failed to attract attention in any portion of the sea which 

 has been at all efficiently dredged*. 



The contents of the three Tables (IV., V., and VI.) added together give the 



* The following northern Mollusca have been identified by Mr. Jeffreys from the 

 Mediterranean, but are not known elsewhere south of the north of Scotland or Shetland 

 Sea: Pecten aratus, P. vitreus, Lima Sarsii, Leda pygmaa, Scissurella crispata, Aclis 

 Walleri, Cerithium metula, &c. ; the occurrence also of the following in the Mediterranean 

 is yery unexpected : Terebratula caput-serpentis, Crania anomala, Pecten septemradiatus, 

 Axinus Croulinensis, Chiton Hanleyi, Propilidium ancylo'ides, Rissoa abyssicola, Scalaria 

 Trevelyana, Odostomla Scillce, Sulla utriculus, &c. 



