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DR. T. S. COBBOLD ON ENTOZOA. 165 



examined separately, displayed internally that advanced condition of the embryo termed 

 proscolex by Van Benedeu. 



Ijorua fflauctis ; L. tridaotylua ; TJriatroile; Alca tarda; Colymbus aeptentrionalis. — 

 In the months of December and January, 1854-55, 1 obtained from the common Grey Gull 

 abimdance of Tetrabothriuni cylindraceum (the Bothriocephahis macrocephalus of Dujardin) 

 and Echinostomum apinuloaum. The latter (figs. 68-72) is usually described as a Distoma, 

 l)ut 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 a peculiar zigzag conformation, the caeca alternating in parallel 

 rows. In the small intestine of the Kittiwake I have also constantly found Tetrubothrium 

 cylindraceum, and from the same situation in the Red-throated Diver quantities of T. 

 macrocephahmi, which Diesing — correctly, I think — regards as distinct from the former. 

 From the oesophagus and proventriculus of the Auk and common Guillemot I have pro- 

 cured, diiring 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 Tceiiia Colymbi Troiles ; 

 I have not been able to satisfy myself, however, that this species is distinct from Tetra- 

 bothriuni macrocephalmn. 



Phasianua pictua ; Tetrao urogallua. — Both caeca of a Gold Pheasant, dissected on the 

 7th of January, 1856, were found enlarged to three or four times their natural vridth, 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 Frolich. 

 From, the intestine of a Capercailzie, examined in the spring of the previous year, were 

 procui-ed numerous specimens of Trichosoma longicolle ; and also from the subcutaneous 

 areolar tissue overljTng the great pectoral muscle, a solitary entozoon resembling Ligula 

 reptana. 



Mua musculus ; Felis catus. — Fresh experiments are not required to determine the now 

 weU-estabUshed fact in regard to the Cysticercus faseiolaris of the Mouse being the imper- 

 fectly developed Tcenia crassieollis 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 taenioid 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 Dochmima tubceformia, the only other 

 worm I have seen in the domestic Cat is the Tcenia elliptica, but, like Dujardin, I have 

 been unable to obtain its head. 



Lepna cuniculua; Cania familiaris. — ^The experimental researches of Von Siebold, 

 Kucbenmeister, Leuckart, and other continental helminthologists, have sufficiently esta- 

 blished a mutual relation between Cysticercus jyisiformia and Tcenia aerrata, hereby 

 affording an additional instance of the truth of Steenstrup's law of alternate generation. 

 I am not aware if any entozoologist in this country has attempted to repeat their experi- 



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