Vou. 2] Ritter —The Pelagic Tunicata. 107 
1895. Die Pyrosomen der Plankton-Expedition. Ergebnisse der 
Plank.-Exped. der Humboldt-Stiftung, Bd. IT, E. b. Fullest 
most resent treatise on the structure and classification and 
distribution of the group. New species: P. aherniosum, P. 
minimum, and varieties levatum and tuberculosum of P. at- 
lanticum. 
Todaro, F. 
1902. Sopra gli organi escretori delle Salpidi. Rend. Acead. Lincei 
(5), Vol. 11, Sem. 1, p. 405-417. In addition to deseription 
of renal organ in Salpa, proposes genus Helicosalpa. 
Traustedt, M. P. A. 
1885. Spolia Atlantica. Bidrag til Kundskab om Salperne. Vidensk. 
Selsk. Skr., 6 Raekke, naturvidenskabelig og mathematisk. 
Afd. II, 8 p. 339-400. Most useful paper on the classifica- 
tion of Salpa yet published. 
1893. Die Thaliacea der Plankton-Expedition A. Systematische Bear- 
beitung. Ergebuisse der Plankton Expedition, Bd. IT, Weide 
Uljanin, Basilius. 
1884. Die Arten der Gattung Doliolum im Golfe von Neapel, ete. 
Fauna und Flora des Golfes von Neapel, Monographie X. 
The most extensive treatment of the genus yet published. 
Vogt, C. 
1854. Recherches sur les Animaux inférieurs de la Méditerranée. 
Second mémoire, Sur les Tuniciers nageans de la Mer de 
Nice. Mém. de 1’Institut national genevois, II. Complete 
list of species of Salpa described up to date of the memoir, 
with association of the two generations of each species; 
budding in Salpa, pp. 5-61. Genus Anchinia, pp. 62-73. 
Genus Appendicularia, pp. 74-86. Genus Pyrosoma, pp. 
87-96. Six plates, illustrating all the genera. 
