LEPTOCLINUM. 17 



2. L. ASPERUM, Milne-Edwards. 



Mem. Asc. Comp. p. 298, pi. 8, fig. 3, 3». 



Closely resembling the last, witli whicli it occurs, but usually 

 white or pale, and rough with conical tubercles placed near each 

 of the buccal orifices. 



Common ; first recorded as British by Mr. W. Thompson, who 

 found it in the same localities with the last species. 



3. L. AUREUM, Milne-Edwards. 



Mem. Asc. Comp. p. 298, pi. 8, fig. 4, 4». 



Similar to the two last species, but distinguished by its uniform 

 chamois-yellow colour. The buccal orifices are closer than in L. 

 asperum, and more deeply lobed. 



Dredged in Strangford Lough by Mr. Hyndman and Mr. W. 

 Thompson. 



4. L. GELATiNosuM, Milnc-Edwards. 



Mem. Asc. Comp. p. 299, pi. 8, fig. 1, 1». 

 Plate A, fig. 5. 



Distinguished from all the other species by its gelatinous con- 

 sistence, and the semi-transparency of the common integument. 

 The individuals have yellow abdominal viscera, and are arranged 

 irregularly around a common cloaca. 



" On the roots of Laminarite in Belfast Bay," W. Thompson, 

 Ann. Nat. Hist., 1844. "A gelatinous compound Ascidian, 

 probably L. gelatinosum, is common on the south coast of Eng- 

 land," Mr. Alder. 



5. L. LisTERiANUM, Mihic-Edwards. 



" Poly clinum," Lister, Philosophicil Transactions for 1834, pt. 2, p. 382, pi. 



12, fig. 1. 



A grey slimy crust, speckled with white and black ; a circle of 

 dark spots around the buccal orifice of each individual. 



Investing algse at Brighton, Mr. Lister. An interesting account 

 of the structure and economy of this species is given by the most 

 accurate microscopical observer who first discovered it. 



VOL. I. D 



