164 MR. F. E. BEDDARD ON WORMS [Feb. 1 6, 



no reasons either for believing or disbelieving that Vaillant's Peri- 

 chceta cingulata is the same species as Scbmarcla's PerichcBta 

 cingulata. 



In the specimens which I examined there is no trace of the 

 natural colour left ; the worms are a pale brownish grey — the 

 clitellum a darker brown. As they do not agree with any Perichceta 

 of which there is an adequate description, I give them the new name 

 Perichceta taprobance. 



There are only four species of Perichceta which agree with the 

 present in possessing only a single pair of spermathecse, so that it is 

 more easily to be discriminated than sp?cies which possess the more 

 typical number of three or four pairs. The species in question are 

 Perichceta sangirensis, Mich. \ Perichceta ceylonica, F. E. B. ^ 

 Perichceta quadragenai-ia, E. P., and Perichceta elongata, E. P. 

 Perichceta taprobance differs from the last two species in a number of 

 points ; it will be sufficient here to mention one point of difference only 

 for each species. Perichceta taproban<s differs from Perichctta quadra- 

 genaria in the size and form of the spermathecal appendix ; from 

 Perichceta elongata in the characters of the •' prostate" ; from Peri- 

 chceta sangirensis in the absence of a dilated sac at the distal 

 extremity of the atrium. Perichceta ceylonica is distinguished by 

 having two pairs of atria. 



Perichceta taprobance is a stout worm, measuring about 80- 

 100 mm. ; the largest specimen was 105 mm. in length; an in- 

 dividual measuring 84 miUims. in length had a breadth of 6"5 mm. 

 and was composed of about 114 segments. 



The worm undoubtedly belongs to the restricted genus Perichceta, 

 although, as will be seen presently, one of the distinctive characters 

 of the genus is absent : the setcB form continuous rows and are 

 numerous ; on the first setigerous segment of one specimen I counted 

 52 setse, on the fifth 81, on the twelfth segment of the same indi- 

 vidual there were 74, on the twenty-fifth 67. The seta. formula 

 is therefore as follows : — 



Segment I. V. XII. XXV. 



52 81 74 67 



The setse are present on all the clitellar segments and form complete 

 circles. Their form is not different from that of the setse elsewhere. 

 Those upon the hinder segment of the body are nearly twice as long 

 as those upon the anterior. 



The clitellum is composed of the usual three segments, but is a 

 little indistinct at both ends. 



The ovidncal pore is single and median ; it lies in front of the 

 circle of setse of segment xiv. 



The atrial pores are upon the xviiith segment and are sometimes 

 very prominent — forming conical elevations — owing to a protrusion 



"^ " Oligochaeten des naturhistorischen Museums in Hamburg, IV.," Jahrb. 

 Hamburg. wis3. Anst. viii. p. 35. 



2 " Notes on some Earthworms from Ceylon and the Philippine Islands, &c.," 

 Ann. & Mag. Nat. Hist., Feb. 1886. 



