PRONEOMENIA INSULARIS. 91 



save for a slight flattening of the ventral surface, measured about 1.5 mm. in 

 diameter and terminated anteriorly by a rounded extremity (Plate 8, fig. 4). 

 There is no crest. Its enveloping cuticle, of the usual yellow color, is compara- 

 tively thick and contains large numbers of tapering spicules with rounded ends 

 (Plate 37, fig. 16). Another type of spine occurs in the deeper layers of the cuticle 

 in the form of relatively short basallj' truncated bodies which are in contact 

 with a stalked cell of the hypodermis. In the case of the larger spicules of this 

 character the sharp distal point may protrude freely above the cuticle. 



The anterior pedal gland is relatively voluminous, extending forward as far as 

 the cirrose area, posteriorly to the front end of the oesophagus and filling nearly 

 all of the visceral space between these two boundaries. As has been noted in 

 other species of the genus this gland opens separately into a comparatively lai'ge 

 space situated behind the mouth opening and continuous with the front end of 

 the pedal furrow. Posteriorly this organ passes without a sharp line of demarca- 

 tion into the pedal gland proper that holds the same relation to the animal as 

 in the preceding .species, but in bulk and in size of its cells it is probably twice as 

 large. Behind the opening into which the anterior pedal gland pours its secre- 

 tion the foot commences as a low median ridge that gradually assumes its fidl 

 size though this is considerably short of that of the foregoing .species. 



The opening of the atrium holds the same position and is of the same rela- 

 tive size as in P. haivaiiensis (Plate 8, fig. 4). The ridges and the cirrose area 

 are likewise very similar in the two forms. The ciliated ridges are not so high 

 in this species owing possibly to the amount of contained blood and the cirri, 

 somewhat more slender than in the foregoing species, are united by their bases 

 into groups of two or three. 



The junction of the atrial cavity and the pharynx is characterized by a 

 ridge similar to that of the preceding species, but is not farther marked by the 

 presence of a dorsal salivary gland. A very few relatively large cells are situated 

 among the nerve fibres passing out from the brain, but while they are in the 

 correct position for the unpaired gland no ducts have been discovered. 



The paired salivary glands present the same general appearance as in P. 

 hawaiiensis. In the present specimen each organ extends from its opening at 

 the sides of the forward end of the radula backward twice the distance from the 

 front end of the animal to the opening of the salivary duct. Beyond this point 

 the remaining portions of the body are missing. The cells are of the usual high 

 columnar type and are more vacuolated than in any specimens of the preceding 

 species. 



