APPENDICULARIAE. 65 



causing the death of the animal. The testes acquire an opening 

 to the exterior at the time of sexual maturity. 



Budding does not take place. What little is known of the 

 development * appears to indicate that it does not differ 

 essentially from that of other Ascidians. The first Appendicu- 

 larian was discovered by Chamisso, who gave it the name 

 Appendicularia. For a long time the systematic position of 

 these forms remained obscure. By many zoologists they were 

 regarded as larval Tunicates, but it was Huxley who dis- 

 covered their spermatozoa and to whom belongs the merit of 

 having first recognized them as members of the'tunicate phylum. 



Appendicularia Cham., capsule ovoid, stomach unilobed, rectum enor- 

 mous, testis single. Oikopleura Mertens, capsule large, stomach bilobed, 

 mouth with ventral lip (Fig. 54) ; tail very long. Vexillaria J. Miiller, 

 special muscles traverse the body and are inserted on to the viscera. Stego- 

 soma Chun, capsule unknown, stomach with liver, surface-waters and deep 

 sea to 1,000 fms. Megalocercus Chun, the largest of all known genera, 

 length of body 8 mm., total length 30 mm., capsule unknown, with a body- 

 wall musculature similar to that of the Salps ; Med., 600-900 fms. Folia 

 Lohmann, capsule unknown, tail long, genital mass single ; Atl. Althoffia 

 Lohmann, warm parts of Atl. Fritillaria Q. and G., body elongated, con- 

 stricted in the middle at the attachment of the tail, a fold of the dorsal 

 integument forming a hood over the head (Fig. 55), testis usually single. 

 Kowalevskia Lahille, capsule large with single orifice, and interior marked 

 with projecting ribs ; endostyle, peripharyngeal band, pericardium and 

 heart absent ; pharynx with 4 longitudinal rows (a dorsal and ventral on 

 each side) of solid, ciliated comb-like processes which act as strainers ; Med. 

 and E. Atl. 



* Goldschmidt, Biol. Centralbl, 23, 1903, p. 72. 



Z III 



