52 THE VOYAGE OF H.M.S. CHALLENGER. 



Reproductive Organs liermaplirodite, l.iut the ova and spermatozoa are not mature 

 iit the same time. 



Gemination takes place ; and alternation of generations occurs in the life-history. 



This important family contains the well-known genus Salj^a and its immediate 

 allies. As it is the typical group of the Hemimyaria, its characters are mainly those of 

 that suborder ; and as they will be discussed under the heading of the genus Salpa, it is 

 not necessary to notice them further here. 



The family Salpidaj was formed by Professor Edward Forbes in 1853. It contains 



two genera — Salpa, Forskahl, and Cyclosaljm, Blainville. They ma}- l»e distinguished 



as follows : — 



Salvwje. 



Alimentary canal Alimentary canal 



extended. coiled up. 



I I 



C'l/dosalpa. Salpa. 



Salpa, Forskahl. 



Holothuria, Linn., Sy&t. Nat., eel. x., torn, i., p. 6.37, 17.JS. 



Dagysa, Banks and Solauder, Hawkeswortli's Voyages, vol. ii. p. 2, 1773. 



Holotlmrium, Pallas, Spicilegia Zoologica, p. 26, 1774. 



Salpa, rorskah], Descrip. anim. &c., p. 112 (in part), 1775. 



Dagysa, Gmelin, Linn., Syst. Nat., ed. xiii., 1788-91. 



Biphora, Bruguiere, Encycl. m6th., torn, i., Paris, 1789. 



Thetys, Tilesius, Abbild. uud Beschr. &c., p. 150, 1802. 



Thalia, Blumenbach, Abbild. naturhist. Gegenst., No. 30, 1810. 



lasis, Savigny, Memoires, p. 235, 1816. 



Pegea, Savigny, Memoires, p. 235, 1816. 



Biphm'a, Costa, Fauna del Eegno di Napoli, p. 3. 



lUphora, Sars, Bidrag til S;^dyrenes Naturhistorie, p. 51, 1829. 



I'ierolyra, Lesson, Voy. de la Coquille, p. 378, 1830. 



Duhreullia, Lesson, Voy. de la Coquille, p. 278, 1830. 



Pegea, Macdonald, Trans. Linn. Soc. Lond., vol. xxiii. p. 371, 1862. 



Sulpn, Cuvier, Lamarck, Chamisso, Krohn, Huxley, Vogt, Todaro, Traustedt, and others (in part). 



Body not attached, elongated, with the apertures at the opposite ends. 

 Test gelatinous or cartilaginous ; transparent. 



Mantle with muscle bands which are more or less incomplete ventrall}'. 

 Branchial Sac opening freely into the peribranchial cavity ; no lateral walls. 

 Dorsal Laviinct in the form of a vascular band marking the junction of 

 branchial and atrial sacs. 



