96 PROCEEDINGS OF THE ACADEMY OF [1880- 



plates. The diverticle of the oesophagus nearly as large as the true 

 bulbus. The spermatoduct and the penis as usual, also the vagina ; 

 the spermatotheca of 1.6 mm. largest diameter. No trace of pig- 

 ment on the vagina or penis, and the peritoneum was colorless. 



Another variety of the species, with " brown mantle and yellowish- 

 white papilljB," was dredged by Dall, in Yukon Harbor (Shumagins), 

 in August, 18t4, on sand and stones, at a depth of six to twenty 

 fathoms. 



The individual preserved in spirits was 9.0 mm. long, by a breadth 

 of 6.5 mm., and a height of 4.5 mm. ; the breadth of the foot 4.0 mm., 

 the height of the gill 1.5 mm. The back of the animal densely brown- 

 dotted, especially the circumference of the gill and the free area left 

 in the middle of the gill ; the dorsal papillae all whitish ; the stalk of 

 the rhinophoria and the inferior part of the club densely dotted with 

 brown, also, in a somewhat slighter degree, the outside of the branchial 

 leaves. The under side of the mantle and the upper side of the margin 

 of the foot and, in a slighter degree, the sides of the body and the sole 

 of the foot dotted with an enormous quantity of brownish-gray points. 

 The form as usual. The gill with nine leaves, of which the two pos- 

 terior were much smaller than the others. 



The central nervous system as usual ; the otocysts very conspicuous 

 under the magnifier as chalk-white points. The mouth-tube 2.0 mm. 

 long. The bulbus pharyngeus 2.0 mm. long ; the sheath of the radula 

 projecting 2.0 mm., bent downwards. The armature of the lip-disk 

 (PI. XII, fig. 10, m very like that of the var. albescens (cf. PI. XIII, 

 fig. 4). The buccal crop as usual. The tongue with nine rows of 

 plates; the total number of rows, twenty-five (13 f 3). The large 

 lateral plates as usual ; the djnticulations rather long and somewhat 

 irregular. The number of the external plates (fig. 12) reaching to six. 

 The salivary glands, the oesophagus with its diverticle, the pyloric 

 part of the intestine with its bag (biliary sac), and the liver, as usual. 

 The sanguineous gland rather large, covering, besides the central 

 nervous system, the whole of the bulbus pharyngeus. 



In the lobes of the hermaphroditic gland, masses of zojsperms. The 

 anterior genital mass of the usual form ; the ampulla of the herma- 

 phroditic duct somewhat larger. The spermatoduct as usual ; so, too, 

 the penis, with its armature ; the length of the glans about 0.5 mm. 

 The spermatotheca and the spermatocjsta as usual; also the chief 

 duct (vagina), the cavity of the last filled with sperma. The mucous 

 gland yellowish-white and in the centre (albuminous gland) brownish- 



