ON MEGASCOLEX CGERDLEUS. 87 



tino-tegumentary vessel to the external iutesiinal capillaries. ««/. cap. 

 Intestinal capillaries. Other letters as before. 



Fig. 8. — Vessels at the anterior extremity of the body. The dorsal and 

 ventral vessels are shown, but their branches are shown on one side or the 

 other only. The intestino-tegumentary vessels are shown on the left side 

 only. cer. Cerebral ganglia. N. Nerve-cord. The peripheral capillary net- 

 works belonging to the first Cve segments are diagrammatically shown and 

 numbered, per. cap. 1 — per. cap. 5. The branches of the dorsal vessel (dorso- 

 tegumentary vessels) are numbered i — v. The septa are indicated by a line, 

 and marked iv . v and v . vi. 



Fig. 9. — Slightly diagrammatic view of the vessels in the body-wall, which 

 is supposed to have been laid open by a cut a little to one side of the dorsal 

 median line. The object of this figure is to show the relations of the peri- 

 pheral networks, j.j. are the branches of the intestino-tegumentary vessels 

 which pass to the intestinal wall. A comparison of this figure with figs. 7 

 and 10 will show the whole course and distribution of one of the posterior 

 intestino-tegumentary vessels. 



Fig. 10. — A view from the inside of a portion of the intestinal wall laid 

 open by a lateral cut to show the intestinal capillaries. The dark coloured 

 vessels and capillaries are connected by the branch marked j., and other 

 similar branches not shown, with the intestino-tegumentary vessel. These 

 branches are supposed to be seen through by transparency ; they really lie on 

 the outside of the intestinal wall. Both capillary networks are in reality a 

 little finer and denser than shown in the figure. The origin of the two pairs 

 of dorso-intestinal vessels from the internal lacunar network is shown, and 

 marked 1. 1, k. is the small vessel by means of which the intestino-tegu- 

 mentary system of one segment communicates with that of another in the 

 intestinal wall, the small cut branches shown connected with this pass to some 

 portion of the peripheral capillary networks. 



Fig. 11. — View of the posterior extremities of the dorsal and ventral 

 vessels. 



Fig. 12. — View of a portion of the dorsal vessel cut open along its 

 median dorsal line. Sept. Septa, h. b. Valves in the septal regions ; the 

 anterior one shown entire, the posterior one partially cut away. D. T. 

 Apertures of the dorso-tegumentary vessels devoid of any valves. D. I.^, 

 D. 1." Apertures of the anterior and posterior dorso-intestinal vessels sur- 

 rounded by the circular valves. £. Transverse section through the same 

 piece of vessel in the region of the apertures of a pair of dorso-intestinal 

 vessels to show the valves b'. W. The wall of the vessel. 



Fig. 13. — External view of the region of the male pores from a spirit- 

 preserved specimen to show the median pit. //l,^ and ^/.^ Apertures of the 

 accessory glands. (J. Male pores. 



