44 
Tapeivonn from a Parokeet 
reproductive organs properly investigated and rests upon external 
characters and measurements: the former, of which only one specific 
character (the shape of the receptaculum seminis) is given, was described 
from two greatly macerated specimens without heads. Since, as far as 
I could ascertain, no complete account of any species of this genus 
has been given, I have endeavoured to make the following description 
embrace as many points as possible. 
I wish here to express my thanks to Mr W. H. Edwards, Curator 
of the Birmingham Natural History Museum, for identifying the 
parakeet submitted to him, and to acknowledge my indebtedness to 
Professor Gamble, F.R.S., for the help he has given me in the elucidation 
of some of the more dubious points in the anatomy. 
Occimence. 
The specimens were obtained from the duodenum of a parakeet, 
Brotogerys tirica, which they nearly filled: their heads lay freely in the 
lumen Avithout any attachment to the intestinal walls: this was probably 
owing to conditions produced by the death of the host, for in the caAuties 
of the suckers were fragments of tissue recognisable as portions of 
duodenal villi. The host came originally from Brazil, but had been in 
England about six months. As it was fed upon purely vegetable food, 
the tapeworms must have been introduced when in Brazil, and have 
developed since. This is only the second record of a Cotugnia from 
America, and the first from South America. The effect of the parasite 
upon the host was to cause slow starvation, the bird being very emaciated 
and especially thin upon the breast. 
External Characters. 
The length of adult specimens of this species is approximately 
75 mm. and the maximum width 2 mm. The head (PI. VI, fig. 1) is 
nearly spherical, being 0-45 mm. long and 0-42 mm. wide. It is provided 
Fig. 1.—Hook from rostellum. 
with four suckers with a diameter of 0-081 mm., and a well-developed 
apical rostellum. The latter is armed with a double roAv of hooks, 
0-012 mm. long, of the characteristicDammea type (Text-fig. 1); the shape 
