a remarkable Epizote Oh'gochete. 117 



Opposite this (rlaiidiilar patchy on tlic ventral .'iii-racc, 

 there is a laro;o, nearly circular, sucker-like orf^an, having a 

 diameter of 0"55 mm. in a transverse direction, but sli;^litly 

 less than this antero-posteriorly. Tliis sucker is composed of 

 muscular tissue, the muscles runnini^ partly vertically, and 

 partly concentiically and parallel with the ciicuhir t d^e. At 

 the sides of this or^an, and somewhat behind its transverse 

 diameter, tiiere open a pair of ducts surrounded by thick 

 muscular tissue : these are, I believe, the male ducts, and 

 may be capable of evagination, though they have not been 

 seen in an extruded condition. 



Immediately behind the sucker the body becomes much 

 flattened, and at the same time expandetl laterally, so as to 

 form a large, oblong, or somewhat oval diaC, in length equal 

 to half that of the whole animal. This disc, or " shield," is 

 bordered by a delicate frilled membrane, which takes its 

 origin bentath the posterior and lateral projecting parts of 

 the sucker, and extends round on either side to the anus, 

 which is placed at the posterior end of the " shield. '' 



The hinder part of the intestine can be seen running down 

 the middle line of the shield, even in a specimen which has 

 not been artificially cleared. 



On either side of the shield, on the ventral surface, there 

 is a series of transverse rows of simple chajtae, each clueta 

 being embedded in its own sac with special muscles. Pre- 

 sumably, though this has not yet lieen definitely ascertained, 

 each row corresponds t) a segment. In an adult spicinien 

 the anterior rows are ab lUt 0*12 mm. apart, but the distance 

 between each row and the succeeding one diminishes gradually 

 on passing backward-, the rows nearest to the anus being 

 very closely crowded together. Conversely, the number of 

 cliset^ in the rows steadily increases from before backwards. 

 Thus, in a mature example, which had about 37 rows on 

 either side, there were four bristles in the first row, five 

 in the second, and so on up to twenty or more in the last six 

 fuliy-fornied rows. 



The first row on either side, situated immediattdy beliind 

 and to the side of the sucker, seems invariably to contain 

 four bristles, which are directed backwards, while the 

 succeeding rows have their bristles more or less inclined 

 forwards — very markedly so in the most posterior rows. 



All this armature, consisting of sucker, frilleil disc, and 

 chsetK, serves doubtless as a very efficient means of aiiach- 

 ment to, or locomotion on, the slimy surface of the earthworm. 



10* 



