470 OLIGOCHAETA 



Definition. Length, 80 mm.; number of segments, lao. Setae ornamented, present on 

 eighteenth segment at opening of male ducts. One median papilla between XIX/XX. 

 Hal. — Bermudas; Jamaica; Brazil {sea-shore). '^ 



This species was originally described by myself from specimens obtained on the 

 island of Bermuda' (24). The description, however, was not at all sufficient to 

 recognize the species, and I subsequently arrived at the conclusion that the supposed 

 species was identical with P. littoralis. Michaelsen's description of his P. arenas 

 led me to look into the matter again, and as a result I found that my species from 

 Bermuda was probably identical with this P- arenae. Some of the specimens of 

 Schmaeda's Pontoscolex arenicola proved also to belong to this same species, though 

 it is not necessary on that account to retain this name for the species, for as his 

 figure evidently refers to a ' Urochaeta,' I retain that name for the genus and for 

 a species of what used to be known by Peeeieb's name of Urochaeta hystrix. My. 

 name, however, should evidently have the priority. Since writing the extremely 

 imperfect account of P. bermudensis already quoted, I have re-exjamined the worm, 

 and find myself able to confirm Michaelsen in every particular, though I can add 

 a few minutiae to his description. The male pores open into a long groove which 

 occupies the whole of the segment ; there is, of course, a groove on each side. This 

 and the fact that there is only a slight genital papilla distinguishes, as regards 

 external characters, the present species from P. littoralis. The ornamentation of the 

 setae does not occur, so far as I have been able to make out, in the European 

 Pontodrilus ; the setae are not modified upon the eighteenth segment, and are 

 present. The muscular duct of the spermiducal gland is much more pronounced in 

 the New World than in the Old World Pontodrilus. Michaelsen found the 

 nephridia to commence in the thirteenth segment ; I found that more usually they 

 began in xv, but in one specimen in xiii. The clitellum occupies segments xiii-xvii. 

 In other anatomical characters this species does not depart from P. littoralis. The 

 specimens from Bermudas and from Jamaica had their entire alimentary tract filled with 

 the debris of coral rock. So abundantly was the intestine filled with calcareous d^ris 

 that the body was in places distended beyond its normal size. There was nothing in 

 the gut except this sand ; no traces of vegetable matter for example. One is disposed 

 therefore to think that the worms must nourish themselves largely upon the minute 

 animals (Foraminifera, &c.), living among the coral detritus. The absence of a gizzard 



1 The increase of synonyms is largely my own fault ; Dr. Michaelsen wrote to me to inquire if my 

 P. bermudensis agreed with certain characters of a new species which he had in his possession and afterwards 

 described as P. arenae; I could not see any ornamentation in the setae, expecting something more pronounced 

 than what actually is found. I have since satisfied myself beyond a doubt that these setae are ornamented. 



