206 ON PERICHAETIDAE. 



acterized by the presence of three pairs of papillae on 

 segments XIX — XXI, but has 12 and 17 spermathecae 

 respectively in segments VI and VII; P. papillata with 

 ten pairs of papillae on the segments XIX — XXVIII and 

 7 spermathecae in segments VI and VII; P. sarawac.ensis 

 with four pairs of papillae on the segments XIX — XXII , 

 and 14 spermathecae in segments VI and VII ; P. kina- 

 baluensis, having on segments XIX and XX a single 

 median papilla, like those of i^üéjreffi fused, on segment XXI 

 the left half only developed and in segments VI and VII, 

 11 and 17 spermathecae in each. In Kiikenthal's Ergeb- 

 nisse einer zoologischen Forschungsreise Michaelsen describes 

 another badly preserved specimen of P. Stelleri from 

 Borneo , with 5 and 9 spermathecae in segments VI and 

 VII respectively, and he makes the suggestion that the 

 above-named species of Beddard all could be identified 

 with his P. Stelleri. I think Michaelsen's suggestion quite 

 right, for the number of papillae and spermathecae, 

 characterizing Beddard's different species appear not to be 

 constant, but liable to much variation. 



I had the opportunity to examine a great number of 

 Perichaeta-specimens , collected by Dr. Biittikofer in 

 Western-Borneo (Poetoes Sibau, Nanga raoen , the Liang 

 Koeboeng) ; they agree with each other externally in the 

 presence of a pair of papillae on several segments behind 

 the male pores, internally in the presence of more than 

 one pair of spermathecae in segments VI and VII, and 

 the absence of intestinal coeca. They all I believe must 

 be identified with P. Stelleri and are characterized in the 

 following manner. 



The length of their body varies from 115 to 300 mm.; 

 the number of segments amounts to 150. The colour is 

 is olive-brown, violet on the upper side, often with a 

 dark line in the dorsal mid-line; chaetal circles whitish. 

 Cephalic lobe extending over two-thirds of the buccal 

 segment, which is longitudinally folded. Setae on a pro- 

 minent ring in front of the clitellum , with obvious dorsal 



Notes from the Leyden M^useum, Vol. XX. 



