1880.] NATURAL SCIENCES OF PHILADELPHIA. 95 



forwards, transversely situated, with a largest diameter of 3.0 mm. 

 The renal chamber and the syrinx as in the form from the Pacific. 



The hermaphroditic gland as in this last variety, its white color con- 

 trasting with the hue of the liver. The anterior genital mass of short 

 pyramidal form, with the point outwards, about 4.75 mm. long, the 

 breadth and the height a little less. The ampulla of the hermaphro- 

 ditic gland yellowish-white, forming a single ansa, about 4.0 mm. long, 

 by a diameter of 0.75 mm. lying on the upper part of the back of the 

 mucous gland. The spermatoduct yellowish, about 15.0 mm. long, 

 constricted a little above the middle of its length ; strong, sloping into 

 the penis, which is about 1.0 mm. long. The armature of the penis 

 entirely as in the form from the Pacific, continued backwards in the 

 interior of the spermatoduct for a length of 6.0 mm. ; the hooks 

 rising to the height of about 0.035 mm., nearly colorless.^ The sper- 

 matotheca (PI. XIII, fig. 5a) spherical, of a diameter of about 2 

 mm., greenish or whitish ; the spermatocysta (fig. 56) much smaller, 

 pyriform, yellowish ; both filled with sperma The chief duct (the 

 vagina, fig. 5dd) very long, with several (four) longitudinal folds, which 

 are folded again transversely ; the structure seemed to resemble en- 

 tirely the form from the Pacific ; in the cavity was more or less sperma. 

 The mucous gland yellow and yellowish-white ; the fold of the duct 

 with brownish-gray points, but no black pigment on the lower part of 

 the vagina or penis. 



One specimen of this typical form, with "brown mantle," and in 

 all respects agreeing with the Atlantic, was dredged by Dall at Kyska, 

 in June, 1873, on rocky bottom at the depth of ten fathoms. 



An individual of a (in living state) " yellowish-white " variety was 

 dredged by Dall in Popoff Strait (Shumagin Islands), on rocky bot- 

 tom at a depth of six fathoms. 



The animal preserved in spirits was 10.0 mm. long, by a breadth of 

 6.0 and a height of 4.5 mm. ; the rhinophoria 1.5 mm. high, the eill 

 1.0 mm., the foot 3.0 mm. broad. The color yellowish-white. In the 

 club of the rhinophoria about thirty leaves ; nine branchial leaves ; 

 the anal papill.i with three small protuberances ; the renal pore very 

 distinct on the right side. The genital opening very wide ; the bul- 

 bus pharyngeus 2.0 mm. long ; the tongue with seven rows of plates, 

 the total number of these twenty-six (16 + 3) ; five external 



^ The armature of the penis has been first seen by H. Friele and G. 

 Armauer Hansen (Bidr. til Kundsk. om de Norske Nudibranchiar. Christi- 

 ania, Vidsk. Selsk. Forh., 1875, extras, p. 4). 



