STRUCTURE OP TWO NEW GENERA OP EARTHWORMS. 277 



the left side to show the contained ovary, sp. sac. Coelomic sac involving a 

 second sac, in which lies apex of spermatheca ; the walls are represented 

 as partly cut away. This part is shown more highly magnified in Fig. 35. 

 r. 0. Receptaculum ovorum, represented as being cut open on left side to show 

 funnel of oviduct (of/.). The nerve-cord is removed for the greater part to 

 show the underlying narrow duct of the spermatheca. 



Fig. 42. — Section through atrium at the point where the two vasa deferentia 

 open. 



Fig. 43. — Section through a portion of one of the ventral oesophageal 

 pouches, bl. Blood-vessels, coloured black, sh. Peritoneal covering, n. 

 Intra-cellular part of lumen. 



PLATE XX. 



Hyperiodrilus africanus, Heliodrilus lagosensis, Nemertodrilus 

 griseus, Teleudrilus ragazzii, and Eudrilus. 



Fig. 44. — Hyperiodrilus. Diagram of male reproductive organs, s. c. 

 Sperm-sac. v. d. Vas deferens. Atria and testes also shown. 



Fig. 45. — Hyperiodrilus. Longitudinal section tlirough duct, leading 

 from egg-sac. c. Outer, c'. Inner peritoneum. 



Fig. 46. — Hyperiodrilus. Supra-intestinal vessel, enclosed within a 

 peritoneal space, which is divided by trabeculse. In the interstices lie clumps 

 of cells. The perihsemal sac is connected to the dorsal vessel {d, vess.) by a 

 mesentery. 



Fig. 47. — Hyperiodrilus. Dissection of the anterior end of the worm. 

 sp'. Anterior, sp. Posterior of thickened intersegmental septa, ces. sac. 

 CEsophageal pouches, ca. Calciferous glands, sp. Coelomic sac, connected 

 with perioesophageal ring, seen anteriorly, v. d. Vas deferens, at. Atria. 

 g. First of posteriorly-situated gizzards. The segments are numbered from 

 the 6th to the 17th. 



Fig. 48. — Heliodrilus. A few of anterior segments to show overlapping 

 and interconnection of thickened intersegmental septa. 



Fig. 49. — Hyperiodrilus. Kipe {b) and nearly ripe {a) ovum. z. r. 

 Zona radiata, v. Vitelline membrane. 



Fig. 50. Hyperiodrilus. Germinal cells from ovary. 



Fig. 51. — Hyperiodrilus. Section through ovarian sacs, to show their 

 interconnection, v. b. Ventral blood-vessel. 



Fig. 52.— Heliodrilus. Gizzards and commencement of intestine. 



Fig. 53. — Eudrilus. Diagram of female reproductive system, ov. Ovary, 

 surrounded by a sac continuous with a duct {od.). ov'. Second ovary, sur- 



