414 Proceedings of Royal Society of Edinburgh, [july 2, 
such as that described above obeys Ohm’s Law in so far as constant 
currents are concerned. I think, however, that a galvanometric 
method, being more sensitive than the above, would indicate a 
discrepancy. 
3. The Metamorphosis of British Buphausiidse. By George 
Brook, Lecturer on Gomparative Embryology in the University 
of Edinburgh, and W. B. Hoyle, M.A. (Oxon.), Naturalist 
in the “ Challenger ” Expedition Office. 
(Abstract.) 
Dana, in his Report on the Crustacea of the North Atlantic 
Exploring Expedition, described a number of genera founded on 
larvae of various Crustacea. Of these genera Calyptopis, Furcilia, 
and Gy^'topia were shown by Claus in 1863 to represent three stages 
in the development of the Euphausiidae. Metschnikofif, in 1869, 
described a still earlier stage under the name of Metanauplius ; and 
in 1871 the same investigator was enabled to show that the young 
Euphausiidae are hatched as true Nauplii, having a rounded body 
and three pairs of swimming appendages. 
G. 0. Sars, in his account of the “ Challenger ” Schizopoda, was 
enabled to follow a portion of the metamorphosis of several genera. 
He figures the following : — 
Nyctiphanes australis — 3 Calyptopis stages. 
Euphausia pellucida — 2 Calyptopis, 3 Furcilia, 2 Cyrtopia, and 
a post-larval stage. 
Thysanopoda tricuspidata — 2 Calyptopis, 2 Furcilia or Cyrtopia, 
with portions of larvse in other stages. 
Nematoscelis rostrata — 2 Furcilia or Cyrtopia stages. 
Euphausia sp. % — early Furcilia stage. 
Hone of these species have been found in British waters. Our 
common West Coast species are — Nyctiphanes norvegica and Boreo- 
phausia Raschii ; to these we are enabled to add Boreophausia 
inermis and Thysanoessa borealis. One or two other species have 
been recorded as British, but, so far as we know, have not yet 
been met with on the West Coast of Scotland. 
Nyctiphanes norvegica occurs abundantly in the Clyde area, in 
