PRONEOMENIA ACUMINATA. 215 



that in Neomenia carinata Wiren (1892) has described a large accessory penial 

 gland whose relations bear a close resemblance to the state of affairs in the present 

 case. 



In conclusion it may be added that the members of the genus Neomenia 

 can scarcely be considered primitive. The complexity of the reproductive 

 system especially, with its penial spines and glands, seminal vesicles, and recep- 

 tacles, appears to indicate that the genus stands in about the same relation 

 to the primitive mollusc that the pulmonates do to the prosobranchs. 



Proneomenia acuminata Wiken. 



One specimen of this species was dredged in the Straits of Florida (>Sta. 

 5 Be) at a depth of 152-229 fathoms; a second was taken south of Martha's 

 Vineyard, Mass. (St. 893 Fk) at a depth of 372 fathoms; while a third came 

 from practically the same location (Sta. 2547 A) at a depth of 390 fathoms. 

 The first is somewhat distorted, and in a normal state probably measured 

 not far from 20 mm. in length by 1.7 mm. in thickness: the second is 23 mm. 

 long by 1.8 mm. thick; the third measures 30 mm. in length by 1.7 mm. in 

 diameter. The anterior end is bluntly rounded (Plate 5, fig. 3), while the 

 posterior extremity terminates in a rounded point, and owing to the large size 

 of the cloacal opening it is probable that in life its borders can be widely expanded 

 as in the case of Ichthyotnenia ichthyodes. 



The atrial opening, surrounded by rounded, prominent hps, is distinctly 

 separated from the ventral groove whose anterior excavation, the outlet of the 

 anterior pedal gland, is invisible externally though in decalcified material it 

 shows faintly through the translucent cuticle. While the outline of the outlet 

 is somewhat irregular in form it consists, generally speaking, of hemispherical 

 diverticula extending laterally a short distance from the ventral groove. 



The anterior pedal gland is a voluminous organ occupying most of the 

 visceral cavity between the region of the radula and the outlet of the dorsal 

 saUvary gland. Although the cells are of varying size, o^dng to age or the 

 amount of secretion they contain, all agree in being more or less pyriform with 

 an irregular somewhat varicose ductule leading to the exterior of the body. 

 The secretion itself is invariably finely granular, staining intensely in Delafield's 

 haematoxylin, and usually fills the cell. As is the case generally with the 

 Neomeniidae the ductules open by intercellular channels into the anterior end 

 of the ventral furrow. 



