430 OLIGOCHAETA 



pores ; on XIX a pair of papillae just behind and to outside <f male pores. Sperma- 

 thecae in VIII, IX each, with a diverticulum. Sperm-sacs in XI, XII. Last heart in 

 XIII. Hab. Vpolu. 



I have commented above as to the limited clitellum which exists apparently in 

 this and in some other species. The genital papillae seem to be particularly small. 



(66) Perichaeta aspergillum, PERKIER. 



P. aspergillum, PERRIER, Nouv. Arch. Mus., 1872, p. 118. 



Megascolex aspergillum, VAILLANT, Annele's, p. 76. 



non P. aspergillum 1 , BEDDARD, Q. J. M. S., vol. xxviii, 1888, p. 401. 



Definition. Length, 370 mm. Clitellum, XIV XVI, with setae on all its segments. Setae, 



eighty in number on certain of the segments. Papillae grouped in masses of nine to 



eleven in proximity to male pores and to spermathecal pores. Spermathecae, two pairs 



in VII, VIII. Hab.? 



This species comes nearest to P. bermudensis under the description of which the 



differences are noted. 



(67) Perichaeta biserialis, PERRIER. 



P. biserialis, PERRIER, C. R., 1875, p. 1044. 

 Megascolex biserialis, VAILLANT, Annele's, p. 76. 



Definition. Clitellum, XIV-XVI 2 . Setae absent on ventral median line, which is bordered 

 by a large seta on each side. Papillae, seven pairs on XIX-XXV. Spermathecae, two 

 pairs. Hab. Philippines. 



I have already (p. 422) commented upon the nearness of this species to my 

 P. acystis. 



(68) Perichaeta robusta, PERRIER. 



P. robusta, PERRIER, Nouv. Arch. Mus., 1872, p. 112. 

 Megascolex robustus, VAILLANT, Annele's, p. 76. 



Definition. Length, 180 mm. Clitellum, XIV-XVI. Setae, 45 per segment. Between the 

 male pores are a pair of papillae. 'Spermathecae, two pairs in VIII, IX. Hab- 

 Mauritius ; Manilla. 



1 This is P. bermudensis (q. v.). 



2 PEKEIEK merely states that the clitellum occupies three segments. 



