Ik*. R. Parnell on a new Species of Poa. 121 



somewhat smaller than the rest of the body, and inserted as it were 

 within it. Miescher was able to observe on these worms the ease 

 with which, by means of their hooked proboscis, they pierce into 

 and bury themselves in the different intestines of the fish without 

 the least injury to them ; he was therefore justified in concluding 

 that the Tetrarrhynchi met with in the pericardial cavity had got into it 

 from the ventral cavity. Miescher suspects that the Tetrarrhynchi 

 were on their way to quit the fish through the membranaceous 

 hind wall of the gill-cavity, behind which they had already collected 

 in considerable number. Miescher further suspects that these Tetrar- 

 rhynchi, having got into the sea- water, search for other animals as an 

 abode ; this seemed to him very probable, as he subsequently often 

 met with similar Tetrarrhynchi at Nice, in the mantles of Loligo 

 sagittata, which were filled with water. I likewise found at Pola 

 quite similar sexless Tetrarrhynchi, provided with an appendage in- 

 serted into the body between the ventral folds of Sepia officinalis, as 

 if they had bored their way from without in order to find a new 

 habitat. Miescher lastly questions whether the sexless Tetrarrhyn- 

 chi might not subsequently change into Bothriocephali of the group 

 furnished with hooks, as the Bothriocephali belonging to this group 

 perfectly resemble in head and neck a Tetrarrhynchus. In favour of 

 the probability of this metamorphosis, Miescher adduces the follow- 

 ing observation : a Notidanus griseus, just killed at Nice, contained 

 in the cavity of the spiral intestine a great number of Bothriocepha- 

 lus corollatus, Rud. : in the articulations of this tape -worm the male 

 and female genitalia were distinctly developed ; beneath the mem- 

 branes of the same intestine there was found, inclosed in a thick- 

 walled cyst of the size of a pea, a worm, to the Tetrarrhynchus head 

 of which two Tcenia joints, without developed genitalia, were affixed : 

 without doubt this undeveloped worm was connected with the Bo- 

 thriocephalus corollatus of the intestinal cavity. 



Creplin* found, like Miescher, similar bodies provided with a tail: 

 on the peritoneum of Esox Belone, he states his having seen a pore 

 at its thick end, agreeing in this respect with Leblond, but he did 

 not any more than myself notice a worm, but only a white granular 

 mass in these sacs. Creplin's observation, that Esox Belone contains 

 in the cavity of its body a remarkable parasite, resembling Tetr. atte- 

 nuatus, two inches in length, is however interesting. 



XXII. — Description of a new Species of Poa. By Richard 

 Parnell, M.D., F.R.S.E., &c.f 



[With a Plate.] 



The Poa about to be described was gathered by Dr. Balfour, 

 Professor of Botany in the University of Glasgow, on a moun- 

 tain called BenVoirlich, near the head of Loch Lomond, during 



" Encyclopadie von Ersch und Gruber, p. 294. 



f The description and drawings are taken from a work on Scottish Grasses 

 about to be published by Dr. Parnell. — Edit. 



