Prof. O. Heer on the last Discoveries in the extreme North. 81 



EXPLANATION OF PLATE IV. 



Fig. 1. An enlarged figure of a minute, smooth, pupiform shell, with an 

 animal like that of Diplom7natina protruding, obtained at the 

 Island of Vatoa, Feejee ; specimen young, not having yet at- 

 tained the thickened double peristome noticed in the text. 



Fig. 2. The animal removed from the shell, and exhibiting the following 

 parts : — a, the labial or buccal plates, composed of thin indu- 

 rated cells resting upon more or less regular courses of square 

 ones ; b, lingual cartilages and fore part of the tongue, with the 

 lingual sac extending backwards from it ; c, tapering tentacula, 

 with the eye at the outer side of the base ; d, the opercular scar 

 distinctly visible (but the operculum was not found in this spe- 

 cies) ; e, tlie auditory sac, containing otoconia ; /, oesophagus ; 

 g, salivary glands ; h, rectum. 



Figs. 3 & 4, respectively, enlarged back and front views of a minute 

 sinistral shell, with trumpet-like evei'sion of a perfectly circular, 

 continuous, and double peristome ; occurring at Norfolk Island. 



Fig. 5. The operculum of the foregoing, highly magnified, as are also the 

 following figures. 



Fig. G. Lingual cartilages, odontophore, and sac. 



Fig. 7. Ear-sac, with otoconia. 



Fig. 8. Buccal plates, the lingual teeth resembling the following. 



Fig. 9. Two transverse rows of the lingual dentition of one of the Diplom- 

 inatinee of Lord-Howe Island. 



Fig. 10. Ditto of Cyclophorus. Isle of Pines. 



There is in nature even a closer resemblance between the external 

 lateral teeth of these two tongues than is exhibited in the figm*es. 



Haslar Hospital, June 5, 1869. 



IX. — The last Discoveries in the extreme North. 

 By Oswald Heer*. 



The high northern latitudes contain a region larger than half 

 Europe, and which, although less distant from us than most 

 other parts of the world, is still entirely unknown to us. For 

 a long time we have been trying to peneti*ate it. There, in 

 fact, ought to be the shortest route from Eui'ope to the East 

 Indies and Western America. The search after this perfectly 

 practical result, the discovery of a ncAv maritime course, has, 

 during the last three centuries, led to the greatest sacrifices; 

 but, in spite of repeated efforts, the problem remains unsolved. 

 To the present moment the 82nd parallel of north latitude 

 marks the limits of an unexplored and always icy region, at 

 the gates of which the bravest men have beaten in vain. We 

 must even add that we have lost all hope of one day discover- 

 ing a maritime route leading to the Indies across the polar 

 seas. 



• Translated bv W. S. Dallas, F.L.S., from the * Bibliotheque Univer- 

 selle,' tome xxxi.x., April 1869, pp. .512-543. 



