106 STROPHOMENIA SCANDENS. 



others for most, of their course, become united above the pharynx shghtly 

 behind the dorsal pharyngeal fold. 



At the junction of the labio-buccal connective and anterior dorsal commis- 

 sure a third nerve arises probably to be considered the subradular connective. 

 A short distance distal to its origin it originates two, sometimes three, small 

 nerves which may be traced deep into the pharyngeal musculature in the neigh- 

 borhood of the radula. Still farther outward a small ganglion is attached to it 

 by a small stalk and between these two bodies the main fibre continues to com- 

 plete the commissure. 



In the posterior part of the body the pedal ganglia decrease rapidly in size, 

 and become lost to view without being directly connected with the lateral cords. 

 In this region the last four or five commissures are more than usually crowded 

 together. The last three connectives on each side become united before enter- 

 ing the posterior end of the lateral ganglia, which here break up into four strong 

 branches that pass backward, and after dividing repeatedly become lost in the 

 walls of the cloaca and body including the posterior elongation. At the point 

 where these nerves arise the lateral cords are joined bj' means of the customary 

 suprarectal commissure. 



Strophomenia scandens, sp no v. 



Three specimens of this species were taken attached to a colony of Acanlho- 

 gorgia armata dredged in the vicinity of Bird Island (Sta. 4156) at a depth of 

 286-568 fath. where the bottom was white mud and foraminiferous rock and the 

 temperature was 45.8 F. The bodies of these animals were wrapped about the 

 stems of the corals as shown (Plate 2, fig. 1), but none of the polj^ps in their 

 immediate vicinity exhibited a shrunken appearance as though these molluscs 

 had been indulging their appetites as in the case of Drepanomenia. The con- 

 tents of the alimentary canal consisted only of a small amount of a finely 

 granular substance. 



The largest specimen measured 39 mm. in length and 2.1 mm. in diameter; 

 the smallest was 32 mm. long with a thickness of 1.6 mm. The two ends of the 

 body are similar in appearance, the posterior being slightly more slender and 

 pointed (Plate 2, fig. 1). In cross section the body is in general nearly circular, 

 but in both of the specimens at hand the ventral surface is slightly flattened. 

 The atrial opening is an elongated slit surrounded by rounded lips, behind which 

 the ventral furrow commences and posteriorly is continuous with the cloacal 

 opening also subterminal in position. 



