104 CATALOGUE OF THE MOLLUSCA 



conical, but not much produced, and when retracted, so completely 

 on a level with the surface, as to be imperceptible. Outer tunic 

 soft, transparent, and colourless, shewing the viscera and branchise 

 very distinctly within : the intestine is seen forming a yellowish 

 brown coil ; a bright reddish spot indicates the stomach ; and 

 the ovaries form an opake white central mass on each side. The 

 inner tunic is very thin, soft, and colourless. The branchial sac 

 has about twelve deep and broad longitudinal folds, which are di- 

 vided by transverse bars into small cells, opening externally to- 

 wards the tunic, and, when viewed through its transparent walls, 

 appearing like rows of chains or festoons ; the intermediate re- 

 ticulations are small. The aperture to the branchial sac is 

 fringed internally with a circle of beautifully branched yellow 

 tentacles. Diameter about three-quarters of an inch. 

 Molgula tubulosa, Forb. and Hani. i. 36, t. C, f 5. 



Brought up plentifully on the fishermen's lines at Cullercoats. 



It is always encrusted with sand, but not so deeply as Cynthia 

 ampulla, and there is often a transparent spot, free of sand, at 

 one side, which gives to these little balls somewhat the appear- 

 ance of detached eyes. They are so abundant in some parts of 

 the fishing grounds that they are caught by the hooks in con- 

 siderable numbers, to the great annoyance of the fishermen. 



We cannot find any description agreeing with this species. 

 It appears to us to come nearest to the Ascidia punum of Mul- 

 ler, but our friend. Professor E. Forbes, who has seen our draw- 

 ings of it, refers it to Ascidia tuhularis of the "Zoologia Da- 

 nica." That species, however, is described to be greenish, 

 opake, and verrucose, — while ours is hyaline, transparent, and 

 smooth. It is also stated to be attached by its base to the roots 

 of Fuci : ours is always free. We have thought it best, there- 

 fore, to consider it as undescribed, and to give such details of it 

 as may serve for its recognition in future. 

 M. OITRINA, Aid. and Hanc. 



Body convex, ovate, attached to stones in a diagonal direction 

 by a broad base; nearly smooth, yellowish and semi-transparent, 

 with a deep yellow or orange-coloured patch at the lower end 

 from the viscera appearing through. Branchial aperture sub- 



