598 



MATNARD M. METCALF, 



Fig. 39. The intersiphonal organs of Botryllus gouldi Verrill, 

 seen from the right side. A reconstruction from serial sections. 



Fig. 40. A sagittal section through the intersiphonal organs of a 

 young Sotryllus gouldi Verrill, derived from a bud. X ^00 diameters. 



Fig. 41. A sagittal section through the intersiphonal organs of 

 Botrylloides gascoi Della Valle. X 262 diameters. 



Fig. 42. A ventral view of the organs near the upper end of the 

 pharynx in Poly cy dus renier i Lamk. X 25 diameters. 



Fig. 43. A sagittal section through the intersiphonal organs of 

 Polycyclus renieri Lamk. X 225 diameters. 



Fig. 44. One cell from the posterior portion of the neural gland 

 of Polycyclus renieri Lamk., near the point of fusion of gland and 

 ganglion. X Hl^O diameters. 



Fig. 45. A sagittal section through the intersiphonal organs of a 

 young individual of Distaplia magnilarva Della Valle, derived from 

 a bud. X 365 diameters. 



Fig. 46. A sagittal section through the ganglion and neural gland 

 of an adult Distaplia magnilarva Della Valle. X 100 diameters. 



Fig. 47. A sagittal section through the intersiphonal organs of 

 Amaroecium constellatum Verrill. The section was so thick that 

 certain organs are seen, though not really in the median plane, e. g. 

 the posterior siphonal nerve. X ^^^ diameters. 



Fig. 48. A single cell from the posterior part of the neural gland 

 of Fragaroides aurantiacum Maurice, near the point of fusion of 

 ganglion and gland. X IHO diameters. 



Fig. 49. A single cell from the posterior part of the neural gland 

 of Circinalium concrescens Giard, near the point of union of ganglion 

 and gland. X IHO diameters. 



Fig. 50. A sagittal section through the intersiphonal organs of 

 Leptoclinum albidum Verrill. X 525 diameters. 



Fig. 51, A sagittal section through the intersiphonal organs of 

 Dijilosmia listerianum Della Valle. X ^25 diameters. 



Plate 38. 



Reference 

 a aperture of the duct of the neural 



gland 

 a. s. n anterior siphonal nerve 

 cd. n in Fig. 65 caudal portion of 



the central nervous system 

 C.f ciliated funnel 

 cl cloaca 



cl. a cloacal aperture 

 d duct of neural gland 

 e eye 



e.in in Fig. 66 ectodermal involution 

 en in Fig. 61 endostyle 



letters. 



ep epidermis 



gg ganglion (brain) 



gl neural gland 



in in Fig. 65 intestine 



I in Fig. 52 languet upon the dor- 

 sal lamina 



lu in Fig. 64 lumen of the ovarian 

 sac 



mo in Fig. 61 mouth 



od in Fig. 66 oviduct 



od. a in Fig. 66 aperture of oviduct 



ot in Fig. 65 otolith 



