An Account of the Bird-lice of the Genus Docophorus. 149 
XIX.—An Account of the Bird-lice of the Genus Docophorus 
(Mallophaga) found on British Auks. By James Waterston, 
B.D., B.Sc. 
(MS. received 8th January 1914. Read 26th January 1914.) 
A. Hosts; CoLLectinc; NoRMAL PARASITISM; “STRAGGLING.” 
EXCLUDING the extinct Alca impennis, L., there are six species of Auk on 
the British list. One of these, however, Uria bruennichi, EK. Sabine, is of 
extreme rarity in our waters. The present paper essays merely to define 
what species of Docophorus are normally to be found on the following— 
Alca torda, L., Uria troile, L., Uria grylle, L., Mergulus alle, L., and Fratercula 
arctica, L. For four years I have been well placed for examining these 
hosts, for in Shetland all are to be found in numbers at one season or 
another. Ollaberry lies on a bay off the west side of Yell Sound, some 
distance from the open sea. “Tysties,’ or Black Guillemots, are constantly 
with us; Little Auks come regularly towards the end of the year; Common 
Guillemots and Puffins are common at intervals; and only the Razorbill 
is infrequent in its appearances. During the period of investigation 
parasites have been taken or received by me from a sufficient number of 
the five host species to warrant the conclusions now put forward. 
Upwards of 1000 specimens of WDocophorus from 44 hosts have been 
examined. Between 30 and 40 of the birds have been obtained locally. 
Most of the Guillemots, Razorbills, Little Auks and one of the Puffins have 
been found in a dying or dead condition after gales which, when prolonged, 
cause a heavy death roll among sea-birds. Uvia troile is possibly the 
commonest victim one comes across, but I have never seen U. grylle succumb 
to stress of weather. To correspondents and others who have assisted in 
procuring material, my best thanks are due. These services are elsewhere 
acknowledged in detail. I also desire to thank the Carnegie Trustees for a 
grant in aid of the present research. 
Some notes on collecting, etc., may be offered. Each host has been 
examined as soon after death as possible, and all parasites picked up with 
fine forceps and placed in preservative. For general purposes the strongest 
industrial methylated spirit (up to 95 7) has been employed, as my 
experience of the 70 // usually advocated for ectoparasites has been unsatis- 
factory. In the weaker solution discoloration and maceration sooner or later 
set in, presumably owing to the weakening of the spirit by dilution with 
the juices of the parasites, and through evaporation. This is no great 
disadvantage with males which, as a rule, may be identified in any state by 
