61 



another coecum or small tube, already described and figured in my 

 Sumatra-paper. 



11. Perichaeta posthuma Vaillant. 

 (— af finis Perrier). 

 Celebes : Makassar , where this species seems to be rather common , 



19 specimens. 



Vaillant ') first published a description of this species, based upon 

 a specimen from Java ; four years afterwards Perrier 3 ) gave a rather 

 detailed account of the anatomy of a species from Cochinchina, named 

 by him P. affinis. As I have demonstrated in an earlier paper 3 ), this 

 species must be considered to be identical with P. posthuma. Beddard 

 mentions also examples of this species from Calcutta 4 ), Manila 5 ) and 

 the Bahamas 6 ). 



P. posthuma, though agreeing in the number of spermathecae (4 

 pairs) with P. indica, appears to be distinguishable from this species 

 at first sight, not only by the presence of a copulatory papilla in 

 front of and behind the papilla of the male pores, but also by its 

 bulky and compact appearance. Though this statement is made after 

 spirit-specimens, I believe it must be visible in the living worm also, 

 for it was to be seen in all the present examples, adult as well 

 as young ones; the numerous specimens of P. indica, which I exa- 

 mined, on the contrary showed all a more slender feature. A speci- 

 men of P. posthuma, 60 mm. in length, has in front of the cli- 

 tellum a breadth of 5^ mm. , whereas an example of P. indica of 

 the same length, measures only 4 mm. in breadth. Also the longitu- 

 dinal diameter of the segments differs remarquably in both species, 

 for in a specimen of P. posthuma, 60 mm. in length , the number of 

 segments amounts to 116, whereas an example of P. indica of a 

 length of 120 mm. (twice as long therefore) possesses only 100 segments. 



The cephalic lobe appears entirely to divide the buccal segment with 

 its narrow posterior projection, like as in Lumbricus; the drawing of 



1) Ann. Sc. Natur., Zoologie, 5e Sér. T. X, 1868, p. 228, pi. 10. 



2) Nouv. Arch. T. VIII, p. 106, pi. IV, fig. 66. 



3) Notes Leyden Museum, Vol. v, p. 106. 



4) Ann. a. Mag. Nat. Hist. 1883, p. 214. 



5) ibid. 1886, p. 93, pi. II, fig. 7. 



6) Proc. Zool. Soc. 1887, p. 389. 



