REMARKABLE SPECIES OF DCIIIUROIDS. 3ô 



The anal (/lands (fig. 2o, a.c/.), present in a pair, open into 

 the very short rectum. They are hrown tubes of ()-7 cm. length, 

 fixed at the extreme tip to the body-wall by a long and slender 

 muscular thread. The main canal of the organ is thickly beset 

 all over with tubules, which are either simple or are divided into 

 2-Ö branches (fig. 20). Distally the tubules or their branches 

 pass over each into a relatively large and long funnel-tube of a 

 deep brown color. 



The Segmental Organs. — 1 have devoted special attention to 

 the segmental organs which offer the most striking characteristic 

 of the species. They are present in a very large number (figs. 

 18 and 23, seg.). They were never less than 200 in total 

 number, and in certain individuals I have estimated this to be 

 nearly 400. Moreover, unlike all other known Echiuroids, there 

 is no indication of their segmental arrangement, nor of their 

 strictly paired disjDOsition. On the contrary, they occur densely 

 and irregularly crowded together in two longitudinal zones, one 

 on each side of the ventral nerve-cord, beginning in front just 

 behind the ventral hooks and extending posteriorly to a length 

 of 10-18 cm. In the anterior parts of each zone, some four or 

 five segmental organs stand abreast ; in the middle parts, three 

 (see fig. 18, •::•) ; more posteriorly, two (fig. 29) ; and finally in 

 the posteriormost parts, they occur in a single row. 



Each single segmental organ is a thin-walled, elongate, bottle- 

 shaped tube, measuring 10-12 mm. in length in the fresh state 

 (see fig. 24). Internally it ends with a relatively large and 

 apically situated ciliated funnel (ßi.). To my knowledge, such 

 an apical position of the funnel on segmental organs has not 

 been known before from other Echiuroids. All the specimens 



