| OCR Text |
Show 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 setae such as occurs in so many Earthworms. Perionyx macintoshii is in an earlier stage still; the setae 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. sansibaricus, which seems to resemble it in the alternation of the nephridia and may be identical.) 10. Perionyx excavatus, E. P. P. excavatus, E. Perrier, Nouv. Arch. M u s . t. viii. P. excavatus, F. E. Beddard, P. Z. S. 1886, p. 308. Megascolex excavatus, L. Vaillant, Anneles, t. iii. p. 69. Length 110 m m . ; breadth 4 m m . ; number of segments 165. Colour (in spirit) purplish on the dorsal surface, yellow beneath; clitellum yellowish brown. Clitellum occupying segments xiii. (xiv.)-xvii. Setae : on either side of male pores about 5 longer setae with strong ridges at free extremity ; these lie within the area surrounding the male pores. Dorsal pores commence v./vi. Gizzard very slight in xii. ; a single pair of calciferous glands in xiii. ; intestine begins in xvii.; oesophagus widens out in xii., but becomes narrow again in xiv. Last pair of hearts in xii. Sperm-sacs very extensive, x.-xiii. 11. Perionyx intermedius, n. sp. Length 105 m m . ; breadth 5 m m . ; 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. Spermatothecae 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. 1 P. macintoshii, F. E. Beddard, Ann. & Mag. Nat. Hist. ser. 5, xii. p. 217. Length 249 m m . ; breadth 9 m m . ; number of segments 2611. 1 320 m m . in length ; 244 segments in another specimen. |
