ON MEGASOOLEX CCEBULEUS. 85 



EXPLANATION OF PLATES VI—IX, 



Illustrating Professor A. G. Bourne's Memoir *' On Megas- 

 colex coeruleus, Templeton, from Ceylon; together 

 with a Theory of the Course of the Blood in Earth- 

 worms/^ 



Reference Letters to Blood-vessels. 



D. V. Dorsal vessel. V. V, Ventral vessel. /. T. Intestino-tegumentary 

 vessels. D. T. Dorso-tegumentary vessels. D. I. Dorso-intestinal vessels. 

 V. T. Ventro-tegumentary vessels. H. Hearts, per. cap. Peripheral capil- 

 lary networks, int. cap. Intestinal capillary networks. S. I. Supra-intes- 

 tinal vessels. S. I. I. Supra-intestino-intestinal vessels, a. Vessels passing 

 from a supra-intestinal vessel to a heart, b. Vessels passing from the dorsal 

 vessel to a heart, c. Commissural vessels joining the two supra-intestinal 

 vessels, d. Anterior extremities of the supra-intestinal vessels, e. Posterior 

 extremity of the supra-intestinal vessels. /. Muscular bulbs at the distal 

 extremities of the hearts, g. Branches joining intestino-tegumentary vessel, 

 with periphery capillary networks, h. Vessels from the intestinal capillary 

 networks joining dorso-intestiual vessels. _;. Branches joining intestino-tegu- 

 mentary vessels, with intestinal capillary networks, k. Vessel in the intes- 

 tinal wall (infra -intestinal), passing from the intestino-tegumentary system of 

 one segment to that of another. /. Origin of dorso-intestinal vessels from 

 intestinal capillary networks. 



PLATE VI. 



Pig. 1. — The entire worm drawn from life by Mrs. A. G. Bourne. Natural 

 size. 



Fig. 2. — Ventral view of the twenty-three most anterior segments, m. 

 Mouth, sp."^ and sp." Spermathecopores (vii . viii and viii . ix). ov. Ovi- 

 ducal pores. ^. Male pores. _^/.i and _^/."^ Apertures of accessory glands. 



PLATE VII. 



Pig. 3. — The anterior portion of the worm dissected from the dorsal sur- 

 face. The alimentary tract is represented in horizontal longitudinal section 

 The septa have been cut in such a way as to render visible as much of the 

 organisation as possible. Some of the generative organs are shown on the 

 one side, and some on the other. The segments are numbered i — xix. m 

 Mouth, ph. Pharynx, giz.^ Anterior portion of the gizzard, with straining 



