76 PACHYMENIA ABYSSORUM. 



somatic muscuLitiire extend far forward into the anterior end of the body. The 

 labio-buccal connectives, imbedded in the pharyngeal glands, pass backward 

 about half the length of the pharynx where they join the ventrally placed ganglia 

 (Plate 39, fig. 8). These masses are in turn united by a strong commissure 

 provided in its mid section with several ganglion cells from which a nerve arises 

 and extends backward for a considerable distance attached to the pharyngeal 

 glands. Wliat appears to be a dorsal commissure springs from the upper side 

 of the ganglia, passes dorsally and may be traced here and there amid the glands 

 over the dorsal surface of the pharynx. It has not been followed throughout 

 its entire extent yet I have but little doubt that it is a definite commissure. 

 From the posterior borders of each labio-buccal ganglion a nerve arises and 

 imbedded also in the glands of the pharynx extends for a considerable distance 

 posteriorly before it becomes lost to view. Finally it may be said that the 

 arrangement of the brain and anterior portion of the nervous system is more 

 regular than in the case of Alexandromenia for example, but otherwise there is 

 no fundamental difference. 



In the posterior end of the body the pedal ganglia continue to be united by 

 commissures of large size and practically the same number of connectives unite 

 them with the lateral ganglia placed high up on the sides of the body. In front 

 of the anterior cloacal wall the pedal cords bend dorsally and provided through- 

 out with ganglion cells attach to the lateral nerve masses at the sides of the peri- 

 cardial cavity (Plate 40, fig. 4) . From the posterior end of the lateral and pedal 

 ganglia nerves arise and extend backward along the body wall and in some places 

 pass into the cloacal folds. 



A well-defined dorsal sense organ is present whose location is represented 

 (Plate 39, fig. 2). Owing to the fact that it is of small size, that the cells like 

 those of the hypodermis are not well preserved and because of the oblique 

 direction of the sections its structure has not been accurately determined yet 

 so far as the examination has gone it appears to conform to the usual type. 



The ovo-testis occupies the usual position on the dorsal side of the animal 

 and extends forward to the posterior end of the pharynx. The ova are 

 unusually large and are surrounded by a chorion, but with these exceptions 

 neither they nor the spermatozoa present any especially noteworthy features. 

 The ducts leading from the gonad into the pericardium are of comparatively 

 large calibre. 



In several respects the coelomoducts are remarkable structures and unlike 

 those of any other known Solenogastre. In the vicinity of their inner openings 



