2 W. T. CALMAN. 



throughout, as being the most complete account we possess of 

 the structure of a Compound Ascidiau. 



Our species, whose relation to Professor Herdmau^s (?) 



ignotus I shall again return to, evidently forms the type of a 

 new genus, which at the suggestion of Professor D'Arcy 

 Thompson (under whose guidance this paper has been pre- 

 pared), I propose to dedicate, under the name of Julinia, 

 to the learned naturalist whose researches on the subneural 

 gland and other anatomical features form classical contributions 

 to our knowledge of the Ascidians. 



The specimen was found floating on the surface of the sea 

 in the north of Erebus and Terror Gulf, and Dr. Donald tells 

 me that considerable quantities were seen. As there is nothing 

 in its structure to suggest a pelagic mode of life, the colonies 

 may have been torn from their submarine attachment in shallow 

 water. At the same time the remarkable genus Ccelocormus 

 must be remembered as showing the possibility of a Compound 

 Ascidian leading an unattached life though destitute of any 

 special means of locomotion ; moreover in the present case 

 the extreme elongation of the colony renders it improbable that 

 it could have been supported by a narrow base of attachment. 



External Appearance and General Features of the 



Colony. 



The colony is irregularly cylindrical in shape (PI. 1, fig. 1), 

 measuring 78'5 cm. in length and from 1'5 to 2'b cm. in dia- 

 meter. One end is torn and ragged, while the other is slightly 

 tapered and smoothly rounded. No attaching fibres such as 

 Herdman describes are preserved. Over large areas, particu- 

 larly along one side, the surface presents a decayed appearance, 

 the zooids being absent or scattered here and there and 

 partially macerated. Over the rest of the surface the zooids 

 are arranged in fairly regular round or oval systems (PI. 1, 

 fig. 2), each comprising from about six to twelve zooids. The 

 colour of the whole is yellowish with a tint as though in life it 

 had been orange, the zooids appearing as lighter spots. The 

 buccal orifices are small and six-lobed. In the centre of 



