184 BEDDARD. 



of the body. The segments are very distinct from each other, 

 and convex, suggesting in general appearance the "rattle" of a 

 rattlesnake. The setse, which are larger upon these segments 

 than upon the Xth and following segments, are implanted upon 

 a prominent ridge which looks slightly backward. The set^ 

 themselves are certainly- directed backward. This state of 

 affairs is plainly shown in the accompanying figure (Plate I, 

 fig. 1) and is an exaggeration of what occurs in some other 

 species of Pheretima. It is, however, a very distinctive mark 

 of the present species as compared with others dealt with in 

 this account of the earthworms of the Philippines with the 

 exception of its close ally P. decipiens. The segments which 

 follow, suddenly change their character. The first 4 of those; 

 that is, segments X — XIII, are equisized and of about equal 

 diameter, as a matter of fact, with any of the last 2 or 3 of 

 the "head" series. While the latter are hardly divided into 

 secondary annuli, the segments X — XIII are each composed of 

 at least 3 distinct annuli of which the middle one bears the 

 setse implanted upon a slight ridge. This secondary annulation 

 is of some importance because it is usually dealt with in giving 

 the characters of various species. It is clear from the condi- 

 tions met with in this Pheretima that the number of secondary 

 annuli is a character which must be made use of with caution. 

 For in one individual there were 3 annuli, and 3 only, to each 

 of segments X, XI, XII, XIII. In two others, however, the 

 anterior annulus was divided into two, and there were thus 

 4 annuli to each segment. The fourth specimen was too much 

 stretched to permit of accurate observation. In 2 individuals 

 the clitellar segments were plainly visible through the imma- 

 turity of the clitellum, and these segments, much narrower than 

 the preceding, were made up of only 2 annuli each. 



The clitellum occupies the whole of segments XIV — XVI, 

 beginning with the furrow separating segments XIII/XIV and 

 ending with the furrow separating segments XVI/XVII. 

 When fully developed, no segmental boundaries are visible upon 

 it ; but the dorsal pores are visible and thus define the individual 

 segments externally. Nor is there any trace of setse that I 

 could discover. This absence of setse applies not only to the 

 fully developed clitellum, but to the clitellum of less developed 

 specimens. The 4 examples which I have studied illustrate 

 the growth in length of the clitellum as it becomes mature. 

 In two the clitellum showed plainly the boundary lines of its 

 component segments and was not quite so long as the preceding 



