APPENDIX III . 457 
twelve fathoms, where the shells were quite thickly covered with 
the red alge. Seventeen specimens of both species of the red 
chitons were obtained. The chitons are now placed in a separate 
order, Amphineura, and represent the lowest type of the Mollusca. 
They have a shell consisting normally of eight plates, hence the 
name Polyplacophora, the many-plate bearer, is applied to the 
most important of the two suborders. 
A group of beautiful creatures when living, but very difficult to 
preserve, are the Nudibranchs, or the naked-gilled Mollusca. The 
large and handsome Dendronotus arborescens, with a row of tree- 
like gills on each side of the back, and branching appendages on the 
head, was obtained by Professor Packard in Henley Harbour, 
at a depth of four fathoms. A species of Eolis is also reported 
from the same harbour, and Coryphella diversa from L’Anse au 
Loup. A group of small shells, which are usually present in each 
haul of the dredge, are known as Tectibranchs. They are re- 
lated to the Nudibranchs, but have the gills covered, and usually 
a shell varying considerably in form in the different families. 
Cylichna alba, Retusa pertenuis, Philine lima, Scaphander punctos- 
triata, and Diaphana hiemalis are the principal species. 
Each haul of the dredge brings in many other forms of animal 
life besides Mollusca. The large brachiopod, Hypothyris psit- 
tacea, is frequently obtained in from eight to fifteen fathoms, while 
attached to the shells are a number of species of the beautiful 
incrusting Polyzoa, or Bryozoa, and the minute Foraminifera. 
Among the interesting objects of the more open Arctic sea are 
the little Pteropods, or wing shells. Packard reports great numbers 
of the little Arctic pteropod Limacina helicina off Cape Webuc, 
and says they are like winged sweet-peas, the shape of the body 
and colour suggesting the resemblance. Another species, Clione 
limacina, with long wings and bright red tints, belongs to the shell- 
less group Gymnosomata. They sometimes appear in such num- 
bers as to actually discolour the surface of the water. They are 
said to afford food for the Greenland whale. The pteropods 
usually come to the surface in the greatest numbers during the 
night, and can be caught by using a towing-net. 
The land mollusks of Labrador are few and scarce. The slug 
Agriolimax agrestis is reported by Packard from Strawberry 
Harbour, together with the little Pupilla hoppii, Vitrina angelice, 
and Euconulus fulva, variety fabricii. They occur under spruce 
bark and chips in the damp verdure, and represent the few truly 
Arctic species found also in southern Greenland. 
