THE ASCIDIANS 259 



ABBREVIATIONS USED IN THE FIGURES. 



a. s. — atrial siphon. 



d. s. — branchial siphon. 



d. I. — dorsal lamina. 



d. l'g''s. — dorsal languets. 



ec. ap. — ectodermal appendages. 



f-f-^f-Y-^ — folds of branchial sac. 



g: g. — ganglion-gland. 



gon. — gonads. 



liy. — hypophysis. 



m.f. — muscle fibers. 



ov. — ovary. 



P, — peduncle. 



p. i. — intermediate papillae of branchial sac. 



;'. b. — terminal bulb of rootlets. 



r. c. — rectum. 



f. /.' — ultimate rootlets. 



st. — stomach. 



^5/.— test. 



tes. — testis. 



ist. c. — test cells. 



