1880.] NATURAL SCIENCES OF PHILADELPHIA. 105 



the right anterior half excavated (on account of the anterior genita 

 mass) ; the color brownish-gray. 



The heart and the sanguineous gland as usual, also the renal cham- 

 ber and the renal syrinx. 



The hermaphroditic gland by its yellowish color contrasting with 

 the liver, clothing the under side, part of the left side, and its right 

 anterior half. The anterior genital mass rather compressed, about 

 6.0 mm. long by a breadth of 2.0 mm. The ampulla of the hermaphro- 

 ditic duct rather short, sausage-shaped, about 2.3 mm. long, curved 

 and whitish. The larger part of the penis was gone, but hooks were 

 seen in the remaining part as in the typical species. The sperma 

 totheca rather large, bag-shaped, about 3.5 mm. long ; the vagina 

 rather wide, about 10.0 ram. long. The mucous gland white, and the 

 albuminous gland yello wish- white. ^ 



This species seems very distinct from the typical one, by its color 

 and by the different form of denticulation of the large plates of the 



tongue. 



POLYCERATID^. 



This large family, so rich in generic forms, was found represented 

 in the northern Pacific only by two generic types, Polycera and 

 Iriopha. 



POLYCERA, Cuvier. 



Polycera. Cuvier, (1812?), Regne-anitn., 1817, ii, p. 390.^ Regne-anim., 



ed. 2, ill, p. 52. 

 Themisto, Oken, Lehrb. der Zool., 1815, p. 278. 

 Cufaa, Leach, Moll. Britann. Synopsis, 1852, p. 21. 

 Polycera C, Aid. and Hanc, Observ. on the genus Polycera, Ann. Mag. 



of Nat. Hist., vi, 1841, p. 337-342, PI. IX. 

 Limacia, O. Fr. Miiller, Zool. Dan., i, 1781, p. 65-68.^ 

 Phanerobranchus, A. Fredol (Moquin-Tandon), Le monde de la mer, 1864, 



PI. xii, figs. 1, 2. 



* The anterior genital mass was so hardened and altered, tliat the nature 

 of its different components could not be determined with certainty. 



2 According to a note of Hermaunsen, under the genus Themisto, Oken, 

 (Ind. Gen. Malacoz, primordia, ii, 1849, p. 572), the genus Polycera was 

 established by Cuvier, 1812, [but this is probably a typographical error, 

 since, under the genus Polycera itself, he indicates only the year 1817 — 

 Dall,] (cf., 1. c, p. 314). 



' Limacia, Hartm., Neue Alpina, i, 1821, p. 208 [Arion, Fer.). 

 8 



