NOTE OK GYRODACTYLUS ANCHOEATUS. 257 



on the appendix of tlie penis. By means of these bacTcwardly directed 

 points, tJie spicule when introduced into the vagina is said to he re- 

 tained during the copulatory act. These statements,' adds Dr. Eberth, 

 ' are not correct ; the villi of the vagina are larger than the spines 

 of the male, and their points are, on the contrary, directed for- 

 toards.' The latter part of this observation is, doubtless, quite 

 true ; for it is evident that our little spiues are entirely different 

 from the curious villi discovered by Dr. Eberth." 



Dr. Cobbold describes two feeding-experiments (one on a rabbit, 

 the other on a chicken) with the eggs of Trichocephalus qffinis, 

 which were attended with negative results. His communication is 

 closed with an appendix enumerating a variety of entozoa obtained 

 from animals which have died in the Zoological Society's Mena- 

 gerie, Eegent's Park. Some of these will hereafter form the sub- 

 ject of a separate notice. 



Note on the Occurrence of Gyrodactylus anchoratus, Nordm, By 

 C. L. Bbadley, Esq., F.L.S. 



[Read Dec. 6th, I860.] 



In the early part of the present year I took the opportunity of 

 calling attention to the occurrence of Gyrodactylus elegans upon 

 the fins and skin of the common Sticklebacks obtained from the 

 Hampstead Ponds. Since then I have seen the same parasite upon 

 the fins of other fish kept in the same tank with the infested 

 Sticklebats — as the Loach, the Gudgeon, and the Roach ; and it has 

 attacked and lived for several weeks upon the tadpole or young 

 Frog. Gold Carp under similar circumstances have remained ex- 

 empt from G. elegans, but on examining their gills quite recently, 

 I found what appears to be another species, which corresponds to 

 that described and figvired by Dujardin as G. anchoratus. It diflers 

 from G. elegans in being much larger ; the cephalic extremity is 

 four-lobed instead of bifid ; the hooks in the disk are much more 

 developed, and project considerably beyond its margin. There are 

 four distinct, black, oculiform dots arranged in pairs towards the 

 cephalic end on the dorsal sm-face. None of them had the appear- 

 ance of being a " nurse," or of containing ova. 



