DR. T. S. COBBOLD ON ENTOZOA. 165 
examined separately, displayed internally that advanced condition of the embryo termed 
proscolex by Van Beneden. 
Larus glaucus ; L. tridactylus; Uria troile; Alca torda; Colymbus septentrionalis.— 
In the months of December and January, 1854-55, I obtained from the common Grey Gull 
abundance of Tetrabothrium cylindraceum (the Bothriocephalus macrocephalus of Dujardin) 
and Echinostomum spinulosum. The latter (figs. 68-72) is usually described as a Distoma, 
but ought certainly to be generically separated. I find the disc surrounding the head 
capable of being elevated so as to form a kind of hood; and the hooks being connected 
together by an extension of the integument, the coronet resembles the fin of a fish. The 
vitelline organs have à peculiar zigzag conformation, the cæca alternating in parallel 
rows. In the small intestine of the Kittiwake I have also constantly found Tetrabothrium- 
cylindraceum, and from the same situation in the Red-throated Diver quantities of 7. 
macrocephalum, which Diesing—correctly, I think—regards as distinct from the former. 
From the œsophagus and proventriculus of the Auk and common Guillemot I have pro- 
cured, during spring, numerous examples of Ascaris spiculigera; one dissection in the 
case of Uria troile exposing two of these nematodes lodged in the auricle of the heart. 
The intestines of another specimen of this bird contained several individuals of a cestode, 
which has been vaguely indicated by Abildgaard under the title of Tænia Colymbi Troiles ; 
I have not been able to satisfy myself, however, that this species is distinct from Tetra- 
bothrium macrocephalum. 
Phasianus pictus; Tetrao urogallus.—Both ceca of a Gold Pheasant, dissected on the 
7th of January, 1856, were found enlarged to three or four times their natural width, owing 
to the presence of a multitude of dark-coloured tubercles, about the size of peas, the inte- 
rior of each of which contained a coiled nematode, the Ascaris vesicularis of Frölich. 
From the intestine of a Capercailzie, examined in the spring of the previous year, were 
procured numerous specimens of Trichosoma longicolle ; and also from the subcutaneous 
areolar tissue overlying the great pectoral muscle, a solitary entozoon resembling Ligula 
reptans. 
Mus musculus ; Felis catus.—Fresh experiments are not required to determine the now 
well-established fact in regard to the Cysticercus fasciolaris of the Mouse being the imper- 
fectly developed Tænia crassicollis of the Cat; indeed, long before their actual identity 
was demonstrated, the frequent occurrence of a cestoid condition of the Scolex within the 
liver suggested an hypothesis which has since proved correct. In my collection there is a 
specimen of this helminth in the tænioid condition taken from the liver of a White Mouse, 
which is nearly as long as that figured by Bremser. Such examples are by no means 
uncommon. In addition to Ascaris mystax and Dochmius tubæformis, the er 
ave 
worm I have seen in the domestic Cat is the Tænia elliptica, but, like Dujardin, 
been unable to obtain its head. ve 
Lepus cuniculus; Canis familiaris.—The experimental researches of Von Siebold, 
Küchenmeister, Leuckart, and other continental helminthologists, have sufficiently esta- 
blished a mutual relation between Cysticereus pisiformis and Tenia serrata, hereby 
law of alternate generation. 
affording an additional instance of the truth of Steenstrup’s 
I am not aware if any entozoologist in this country has attempted to repeat 23 experi- 
