ASCEDIA MENTULA. 79 



in a single row on a muscular ridge or collar 

 (Plate III, fig. 1) ; they vary considerably in size, 

 number upwards of forty, and are usually placed a 

 little apart, and not far above the margin of the 

 branchial sac. 



The ovary is situated in the loop of the intestine 

 and is seen at both sides of that organ; it appears as 

 a lobulated, compact mass, and does not extend over 

 the walls of the alimentary tube. The male caeca are 



e/ 



conspicuous on the right side of the intestine as white 

 dendritic tufts ramifying over the surface and partially 

 buried in the cellular matter, a thick layer of which is 

 spread over the whole of the digestive organs. 



Professor Edward Forbes considers this to be the 

 commonest of our deep-water Ascidians ; but it has not 

 yet been met with on the north-east coast of England. 

 It appears to be frequently met with, though not very 

 common, on the south and west coasts. Sars states 

 that it extends along the whole of the Norwegian coast, 

 and also occurs in Greenland and North America. His 

 remark that the tentacular filaments are conspicuous 

 between the ocelli, in both orifices, must refer to the 

 internal folds of the apertures which terminate in 

 points above. The tentacular filaments are confined 

 to one aperture and do not appear outside. 



Asriilia titntfiilti, is one of the largest and most 

 uncouth-looking of our native Ascidians, often being- 

 disfigured by extraneous substances and by swellings 

 caused by Modiola TIKI ////>/ </ hi imbedded in the test. 

 Miiller says that it is pilose, but this is an error probably 

 occasioned by some small zoophytes covering the sur- 

 face. Professor Percival Wright informs us that he 

 has met with AxriJin uit-nt/ila, in Bantrv Bay, measur- 

 ing eleven and a half inches long and two and a half 

 broad. A remarkable monstrosity of this species was 

 sent to us from Lulworth Cove by our friend Mr. 

 Jeffreys. It consisted of two perfect Ascidians im- 

 bedded in one test, one of them rising perpendicularly 

 above, and the other lying diagonally across, the base. 



