332 W. BLAXLAND BENHAM. 



which hide the small intercellular part of the nephridium intervening between 

 the " wide tube " and the epidermic pit forming the nephridiopore. cl. Cli- 

 tellar cells. ep. Epidermis. con. tis. Connective tissue. circ. Circular 

 muscles. Ig. mus. Longitudinal muscles. «e/;/i. pore. Epidermal pit, consti- 

 tuting the nephridial pore (which is deeper in the neighbouring sections). 



EiG. 18. — A portion of the nephridial loop of Lumbricus in longitudinal 

 section, passing through some of the dilatations of the blood-vessels, in which 

 are groups of blood-corpuscles. 



Fig. 19. — A transverse section through a part of the nephridium on one 

 half of the second loop, showing the blood-vessels ramifying between the 

 different parts of the tube. 



EiG. 20. — A similar section through the tip of the third loop, to show 

 blood-vessels ramifying between the different parts of the tube. 



Fig. 21. — The apex of the third loop, to show blood-vessels passing among 

 and around the various parts of the tube. It is slightly diagrammatic. 

 Those portions of the blood-vessels which pass behind the tubes are repre- 

 sented only in outline. 



Fig. 22. — A portion of a nephridium, drawn from a living specimen under 

 a high power, to show the complexity of the coils and branchings of the capil- 

 laries; there were no dilatations in this specimen. The outlines, merely, of 

 the nephridial tube are indicated. 



Fig. 23. — Portion of a loop of a nephridium of another worm, in which the 

 dilatations of the blood-vessels were numerous (drawn under a low power from 

 a living specimen). Many of the finer vessels are not shown, nor are the 

 outlines of the nephridial tube. A portion of the septum is shown, with 

 small blood-vessels passing across from it to the nephridial network. 



Fig. 24. — A portion of the same network greatly enlarged, to exhibit the 

 varying size and shape of the dilatations. 



Fig. 25. — The nephrostome of Perichseta malamanieusis, n. sp. a. 

 In longitudinal section, b. From in front. These drawings are taken from the 

 same transverse section through the worm, and the two funnels are quite close 

 together, some five or six occurring in the whole section. The drawing is 

 introduced to show tlie simple character of the nephrostome when compared 

 with that of Lumbricus. ma. Marginal cells, ap. Communication between 

 nephridial lumen and the coelom. 



Fig. 26. — A portion of a section through a nephridium of Brachydrilus, 

 to exhibit the branching of the narrow tube which wraps round the 

 wide tube. The blood-vessels are also shown in black or in grey, according 

 to the relative depth in the section. 



Fig. 27. — A nephridium of an Enchytrseid, to demonstrate the simple 

 character of the nephrostome {st.), the uniform diameter, &c., of the tube 

 {t.), which is embedded in one mass of vesicular cells {c. t.). The external 

 aperture is shown at p. 



