Note on the morphology of the Tunicata. 599 



ov ovum V. d vas deferens 



ovy in Fig. 66 ovary v. m in Fig. 61 visceral mass 



ph. h in Fig. 52 peripharyngeal band x in Fig. 54 nerve fibres running 

 ph. ep pharyngeal epithelium from the ganglion to the cili- 



r in Fig. 61 dorsal raphe ated funnel and the duct of the 



r. d rapheal duct neural gland 



r. n rapheal nerve ?/ in Fig. 65 rapheal portion of the 

 st in Fig. 61 stolon central nervous system 



t testis s in Fig. 55 ventro-lateral process 

 tc in Fig. 66 outer contour of tunic from the gland 



t.n in Fig. 65 trunk portion of 

 central nervous system 



Fig, 52. A ventral view of the intersiphonal organs of Pyrosoma 

 gigantcum. X ^^ diameters. 



Fig. 53. The brain and neural gland of Pyrosoma giganteum, as 

 seen from the left side. X ^^ diameterts. 



Fig. 54. A sagittal section through the intersiphonal organs of 

 Pyrosoma giganteum. X ^00 diameters. 



Fig. 55. The intersiphonal organs of the sexual form of Doliolum 

 mülleri as seen from the right side. (After Uljanin, reference letters 

 my own.) 



Fig. 56. The intersiphonal organs of the larva of Doliolum mül- 

 leri., as seen from the left side. (After Uljanin, reference letters my 

 own.) X 480 diameters. 



Fig. 57. The intersiphonal organs of the Phorozoid (second nurse) 

 of Doliolum affine. 



Fig. 58. A ventral view of the intersiphonal organs of the chain 

 form of Salpa runcinata-fusiformis. X 40 diameters. 



Fig. 59. An oblique section, nearly sagittal, through the inter- 

 siphonal organs of lasis hexagona. X ^^ diameters. 



Fig. 60. An oblique section, nearly sagittal, through the inter- 

 siphonal organs of lasis costata-tilesii. X ^^ diameters. 



Fig. 61. One individual from a young chain of Salpa cylindrica, 

 as seen from the left side. Actual length about 1^/4 mm. 



Fig. 62. A section through a young ovarian ovum of a rat, show- 

 ing the ovum and its follicle and, within the ovum, five (perhaps six) 

 nuclei of follicle cells which have been ingested by the ovum. X ^^^ 

 diameters. 



Fig. 63. A section through one ovum and one testicular follicle of 

 a perfect zooid of Leptoclinum albidum. X ^^^ diameters. 



Fig. 64. A section through the ovary of a zooid of Leptoclinum 

 albidum, the upper part of whose body has been lost by degeneration. 

 X 360 diameters. 



Fig. 65. A parasagittal section, very near to the median line, 

 through the dorsal portion of a tadpole of Ecteinascidia furhinata. 



