882 EEPOKT OF COMMISSIONER OF FISH AND FISHERIES. [4] 



most layers of the atrium. The exterior one, of the second layer of 

 atrium. The third layer of the atrium is not in continuation with the 

 layers of the penis. The penis sheath is very pellucid, and difficult 

 to discovery especially so is its upper margin. Its lower interior sides 

 are covered with numerous diagonal muscles, one end of which is at-^ 

 tached to the body of the penis. In the center of both atrium and penis' 

 is found a continuous row of spermatozoa. The penis is only external 

 in fully matured specimens. 



The oviduct consists of a heavy muscular coating or sack, one end of 

 which is attached to the body wall, the other free in the neighborhood 

 of the lower end of the atrium. This oviduct is extremely heavy which 

 makes it often impossible to discover the nature of the organ covered 

 by the same. 



The testes consist of two oblong amorphous bags, situated in the eighth 

 and ninth setigerous segments, one on each side of the ventral nerve. 

 The ovaries consist of two rounded, sack-like bodies, situated between 

 the ninth and tenth segments, their anterior ends being attached to the 

 body wall of the ninth segment and part of their body to the dissepi- 

 ment between the ninth and tenth setigerous segments. The ripe ova 

 are always found in the broadest end of the ovary, the smallest or least 

 developed ones in the narrowest part of the same (Fig. Ig). 



The receptacle consists of two minute oblong sacks, one on each side 

 of the ventral nerve in the ninth setigerous segment. Their exterior 

 porus is found on the body wall between ajid somewhat in front of the 

 ventral fascicles, not in front of one of them, as in Tubejicini. 



ISTo spermatophores are found in this species, the spermatozoa being 

 simply agglomerated together in pear-shaped or globular balls. In the 

 atrium they form a continuous row in the middle of the inmost cavity 

 (Fig. le, spz). 



The segmental organs resemble those of TuUficini in their general 

 structure. The whole tube of the organ is surrounded by large pellucid 

 cells, sometimes of a globular, sometimes of a more oblong shape 

 (Fig. Ih). In the majority of these a large nucleus is plainly visible. 

 The above cells are found not only surrounding the segmental organs 

 in front of the efferent duct, but also on those behind the same. 



The exterior aperture of the organ is the largest one, and from here 

 the tube tapers gradually towards the interior aperture, at the lower 

 end of which is found two sack-like appendices. The aperture is 

 strongly ciliated (Fig. 1*). 



The integument of the body is very thick, and the body accordingly 

 not very flexible. The worm, when found, therefore, resembles more a 

 small pointed stick or straw, the tail being the most flexible part of the 

 animal. In this respect this worm is unlike most of the other species 

 of TuUjieidw, Avhich, with few exceptions, are lively and very movable 

 animals. 



Body. — The length of the same in alive specimens is generally from 

 35"^"^ to 50™™, and the width between I™'" and 2'"°'. The anterior part 



