DESCRIPTIONS OF EARTHWORMS. 231 



NOTE XXXIX. 

 DESCRIPTIONS OF EARTHWORMS. 



BY 



Dr. R. HORST. 



V. 



On two new Perichaeta-s^ecies 



from Billiton. 



(Plate 10). 



Among the animals, collected by Dr. A. Vorderman in 

 the island of Billiton ^) and presented to our Museum , 

 I met with some earthworms belonging to the genus 

 Perichaeta , which appear to be hitherto undescribed. 



Perichaeta vorderma7ini, n. sp. 



The largest of the two specimens measures 315 mm. in 

 length; the number of its segments amounts to 175. The 

 colour is a yellowish brown, somewhat darker in the an- 

 terior portion of the body ; a region around the male ge- 

 nerative pores and the ridge of setae around each segment 

 are whitish coloured. 



The peristomial segment and the prostomium could not 

 be recognized , as the cuticula has loosened from the body- 

 wall and the buccal cavity is partially everted. The ante- 

 rior three segments have about the same length, but in 

 the succeeding ones the longitudinal diameter is gradually 



1) See p. 149 of this volume. 



Notes from the Leyden JMuseum , Vol. XII. 



