262 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 



phageal region, but in no portion of their course is there a single 

 large tubule as is found in most species of the genus. Throughout 

 their whole extent they consist of fine, branching tubules imbedded 

 in the gelatinous tissiie of the body cavity. 



In the single specimen, I found two pairs of efferent nephridial 

 ducts. The anterior pair was situated a short distance l)ehind the 

 brain, and opened on the ventrolateral aspects of the body, as is 

 common in the genus. The second pair was situated some distance 

 further posteriorly and oj)ened directly laterally and far above the 

 lateral nerve cords (PI. 19, fig. 120). A somewhat similar condition 

 has been described in but few other species of the genus, but A. 

 imparispinos^is and A. forniidabilis^ both from the west coast of 

 America (Coe, -.01, j)p. .52, 55), and Geonemertes (Bohmig, '98, p. 

 512) likewise have efferent ducts opening both above and below 

 the lateral nerves. When passing through the body walls, the 

 efferent ducts spread out widely in the circular muscular layer, as 

 has been noted in other species. 



Blood vascular system. — The blood vessels show few deviations 

 from the condition found in related species. The blood spaces in 

 the head are small, and are imbedded in the parenchyma (PI. 19, fig. 

 119). The three longitudinal vessels are likewise supported in the 

 same tissue. The cells lining the interior of the blood vessels are 

 very large and have a remarkable affinity for stains, as in some other 

 species. 



yervous system and sense oryans. — The brain is voluminous; 

 dorsal commissure of medium size, ventral commissure remarkably 

 large (PI. 19, fig. 119). The brain is buried deep in the tissues of 

 the head (as in Taeniosoma), and the lateral nerves at their origin 

 from the ventral ganglia bend outward toward the lateral walls of 

 the body, but do not reach nearly to the muscular layers. General 

 distribution of nerves as in other species of genus. Lateral nerve 

 cords lie in ventral portion of the l)ody, and are imbedded in the 

 gelatinous tissue of the body cavity (PI. 19, fig. 120). 



The cerebral sense organs are extremely small. They lie in front 

 of the brain and open by short canals to the ventro-lateral aspects 

 of the snout. 



The ocelli are highly developed, and shovv clearly the nerve fibers 

 spreading out inside the pigment cup. 



Be2)roductlve oryans. — The genital pouches commence at the 



