IIG STROPHOMENIA REGULARIS. 



to the pedal ganglia, and at first resting upon the digestive tract and more 

 posteriorly inihodded between the phar.vngeal glands may be distinctly followed 

 to well-defined ganglia in the neighborhood of the outlets of the ventral salivary 

 glands. Owing to the fact that these ganglia are united by a large commissure 

 dorsal to the ventral salivary glands, though ventral to the gut, they probably 

 corresjjond to the labial ganglia. This commissure leads from the posterior 

 ends of the nerve masses which more anteriorly are imited by two more nerves 

 ventral to the phai-ynx. One of these is a simple commissure like the more 

 posterior cue and like it is imbedded in muscles. The remaining one, imbedded 

 in the same manner, is of much smaller size and soon unites with two small 

 ganglia resting against the pharyngeal musculature somewhat ventral to the 

 labial ganglia. These smaller ganglia are united also by a slender commissure. 

 Comparing this system with what occurs in P. lunrmiensis it is probable that thej- 

 form a subradular system which as in Strophovienia scandeiis has persisted, 

 though the sense organ itself has almost if not completely disappeared. The 

 labial ganglia are united also by a dorsal commissure leading out from their 

 anterior surfaces. An unusual abnormality exists in this species in the form of 

 two labio-buccal connectives on one side. One of these is incomplete since it is 

 formed by a branching of the usual connective opposite the middle of the ante- 

 rior pedal gland outlet. The more ventral branch, larger than the dorsal, 

 makes its way to the underside of the pharynx and close to the mid line pursues 

 a course to the neighborhood of the labial ganglia whereupon it bends outward 

 at a sharp angle and unites with its fellow at the anterior end of the ganglion. 



Strophomenia regularis, sj). iiov. 



This species is represented by the posterior end of one animal that, however, 

 is so characteristic as to leave no doubt regarding its relationships. It was 

 found in the liottom of the jar containing specimens of Dendronejithya 

 (Spongodes) sp. and may therefore be considered to have come from the 

 southern end of Honshu Island, Japan (Sta. 3717) at a depth of 75-100 fathoms. 

 The length of the fragment is 9 mm. and the average diameter 1 nnn. Its 

 general outline is represented (Plate 26, fig. 8). 



The coelenterate, with which this species was associated in the jar, was 

 originally preserved in formalin that in decomposing had completely decalcified 

 the fragment. It may be clearly seen (Plate 24, fig. 7), however, that for the 

 most part the spicules are of the usual needle form and are accompanied bj'^ a 

 relatively small number with truncated bases, all being imbedded in a cuticular 



