LIST OF ILLUSTRATIONS 



FIG. PAGE 



664. Balanoglossus ... 2 



665. ,, anterior end 4 



666. ,, development . . 5 



667. Tomaria . 6 



668. ,.'... 6 



669. Cephalodiscus, gelatinous investment . 7 



670. ,, zooid 



671. ,, sagittal section . 9 



672. Rhabdopleura . 10 



673. Ascidia . 12 



674. ,, anatomy ... . 13 



675. ,, mesh of branchial sac . . 14 



676. ,, diagrammatic longitudinal section . 15 



677. ,, transverse section .... 16 



678. ,, hypophysis, ganglion, and associated parts . 17 



679. Appendicularia .... 21 



680. ,, diagram . 21 



681. Botryllus violaceus .... 22 



682. Composite Ascidian, diagram of zooid . 23 



683. Doliolum ... 24 



684. Salpa democratica, ventral view 24 



685. ,, lateral view .... 24 



686. Pyrosoma ... 25 



687. ,, part of section . .25 



688. Development of Clavellina, early stages . . 28 



689. ,, ,, later ,, 30 



690. Larva of Ascidia mammillata ... . 31 



691. Metamorphosis of Ascidian, diagrammatic . . . 33 



692. Doliolum, tailed larva .... 34 



693. ,, asexual stage, lateral view . . . . 34 



694. ,, ,, ,, dorsal ,, . 35 



695. Salpa, late stage of development . . . 36 



696. Amphioxus lanceolatus .... 39 



