222 DORYMENIA PERONEOPSIS. 



division of shell gland become charged with a darkly staining, partially granu- 

 lar, secretion which likewise extends to the narrow canal communicating Avith 

 the cloaca. The terminal section of the coelomoducts is a tube of comparatively 

 small diameter (Plate 5, figs. 5, 8) composed of slender cells fashioned into 

 several inconspicuous folds. Circular muscles form a sheath about it, and 

 radiating bands, probably functioning as dilators, pass from it to the body wall. 



In sections it may be seen that the spiculose investment of the animal 

 extends within the body as far as the external reproductive aperture (Plate 5, 

 fig. 5). What probably function as copulatory spicules occur at the sides of 

 the ventral furrow (openings shown in Plate 5, fig. 8) a short distance in front 

 of the posterior end of the foot. These organs present the form of needle-Uke 

 bodies, so far as can be judged from decalcified specimens, are probably derived 

 from the usual type of spine occurring everywhere in the region of the ventral 

 furrow, and form two groups of from 12-14 on each side of the mid line. Each 

 spine occupies its individual sheath, which extends anteriorly and laterally 

 from the outer opening, and ends bUndly where a single matrix cell is located. 

 While no definite muscles appear to attach to these bodies, the region in which 

 they occur, and in fact the entire border of the cloacal chamber, is highly mus- 

 cular and doubtless can be opened widely, thus bringing these penial spines 

 into an exposed position. 



The type-specimens of this species was taken in the "West Indies" at a 

 depth of 540 meters, practically the same as the habitat of the present speci- 

 mens. Some of Wiren's reconstructions and drawings of various organs appear 

 to be somewhat diagrammatic and do not entirely accord with what exists 

 in the specimens in hand. Accordingly the foregoing detailed description has 

 been arranged with the hope that it may be compared with Wiren's account 

 and the type-specimen. 



Dorymenia peroneopsis, sp. nov. 



A single, unattached specimen of this species was dredged south of Martha's 

 Vineyard, Massachusetts (Sta. 2715A) at a depth of 1,753 fathoms. The body 

 measuring approximately 25 mm. in length by 2 mm. in greatest thickness, 

 is broadly elliptical in cross section with a sUght flattening of the ventral surface. 

 The anterior end is bluntly rounded while the posterior extremity tapers abruptly 

 to a point. From external view no hne of separation exists between the atrial 

 opening and the ventral furrow, and sections show that the usual spiculose 

 bridge is lacking. The outlet of the anterior pedal gland is accordingly located 



