304 AMERICAN JOURNAL 



Station, (on sea weed in sheltered places. They are very- 

 active and when at rest the tentacles are recumbent, like the 

 ears of a rabbit. A.G.) 



Ptbrogasteron marginatus, Pease. Plate 21, fig. 3. 



Mantle lobes, when spread out, oblong cordate, margins some- 

 what waved. Tentacles stout, ear shaped and somewhat involute. 

 On the interior surface of the mantle lobes, three pale lines 

 radiate from the posterior part of the body on its left side and 

 two on the right, one of the latter bifurcate, which probably are 

 the branchiae. 



Color olivaceous green, gradually becoming greenish white 

 beneath ; somewhat remotely dotted with black and opaque white. 



Mantle lobes margined with orange, white and black. There 

 is a tinge of orange at the tips of the tentacles and an oblong 

 white spot on each. The inner surface of the lobes is the same 

 color as without, but paler and fewer spots. 



Length, two and a half inches. 



Habitat. Island of Huaheine. 



Pterogasteron rufescens. Pease. Plate 22, figs. 1, a,b,c. 



Animal rather slender, truncated behind. Color rufous brown 

 passing into whitish beneath, and olivaceous brown on the head. 

 Closely spotted with small, irregular, greenish white spots, which 

 gives the ground color a reticulated appearance. 



Front of the head, in the region of the lips, white. Tentacles 

 lineated with greenish white, and tinged with violet on their 

 outer part. Mantle lobes edged with dark lead color, and an 

 intramarginal orange line. Disk pale with opaque white spots. 

 Inner surface of the lobes edged the same as outside, but the 

 ground color is greenish lead, becoming paler centrally, with 

 whitish spots, and remotely punctured with vermillion. Eyes 

 pale with black pupils. 



Length, one and a quarter inches. 



Habitat. Tahiti. 



Pterogasteron nigropunctatus, Pease. Plate 22, figs 2, 

 a, b, c, d. 

 Mantle lobes rounded behind ; tentacles stout, upper lip 

 bilobed ; locomotive disk small. Color olive green, clouded with 

 darker, paler beneath, and finely reticulately veined with darker 

 green. The whole surface with small irregular whitish spots 

 and punctured with jet black, the latter small beneath, larger 



