1892.] SPECIES OF EARTHWORMS. 689 



from the exterior of the body and lodged in a sac formed by their 

 withdrawal, we should have the sac of penial setse such as occurs in 

 so many Earthworms. Perionyx macintoshii is in an earlier stage still ; 

 the setse in the neighbourhood of the male pores are not modified, 

 but appear to resemble those of other segments. Finally the four 

 species may be thus briefly defined. (I have not included Bourne's 

 Perionyx saltans pending further details, or Michaelsen's P. sansi- 

 baricus, which seems to resemble it in the alternation of the nephridia 

 and may be identical.) 



10. Perionyx excavatns, E. P. 



P. excavatus, E. Perrier, Nouv. Arch. Mus. t. viii. 



P. ececavatus, F. E. Beddard, P. Z. S. 1886, p. 308. 



Megascolex exeavafus, L. Vaillant, Anneles, t. iii. p. 69. 



Length 110 mm. ; breadth 4 mm. ; number of segments 165. 



Colour (in spirit) purplish on the dorsal surface, yellow beneath ; 

 clitellum yellowish brown. 



Clitellum occupying segments xiii. (xiv.)-xvii. 



Setse : on either side of male pores about 5 longer setse with 

 strong ridges at free extremity ; these lie within the area surrounding 

 the male pores. 



Dorsal pores commence v./vi. 



Grizzard very slight in xii. ; a single pair of calciferous glands in 

 xiii. ; intestine begins in xvii. ; oesophagus widens oiit in xii., but 

 becomes narrow again in xiv. 



Last pair of hearts in xii. 



Sperm-sacs very extensive, x.-xiii. 



11. Perionyx intermedins, n, sp. 



Length 10,5 mm.; breadth 5 mm.; number of segments 117. 



Colour (in spirit) with a faint purple tinge dorsally, not nearly 

 so marked as in preceding species. 



Clitellum xiii.-xvii. 



The pit on segment xviii. bearing the atrial pores is shallow and 

 not very marked ; the two pores lie in a transversely running groove 

 and the integument is thrown into a series of folds on either side of 

 the groove. 



Gizzard in vi., not at all prominent. No calciferous glands. 

 Intestine begins in xviii. 



Last pair of hearts in xiii. 



Spermatothecse in viii., ix., each with a small globular diverticulum 

 sessile upon the duct. 



Atria very large and of a loose consistency, extending through 

 three segments, xvii.-xix. Duct comparatively long and coiled. 



12. Perionyx macintoshii, F. E. B. 



? P. macintoshii, F. E. Beddard, Ann. & Mag. Nat. Hist. ser. 5, 

 xii. p. 217. 



Length 249 mm. ; breadth 9 mm.; number of segments 26l\ 

 1 320 mm. in length ; 244 segments in another specimen. 



