140 proceedings of the academy of 



Gasteropoda. 

 Polyceral sp. 



One specimen, dredged in the deeper part of the channel, about 

 an inch long, noticeable for its bright blue and yellow tentacles. 



Aplysia? sp. 



Two specimens of another nudibranch were taken Aug. 3, 1870, 

 as they were floating on the surface of the water in the harbor, 

 and the same species was subsequently several times seen. The 

 animals Ttere quite lively, moving about freely, especially if 

 irritated, by a regular waving motion of the free edges of the 

 tunic. When most contracted, they were of a flattened and some- 

 what irregularly oval shape, some three inches long ; and were 

 capable of stretching out between six and seven inches. Placed 

 in water, the color appeared of a clear warm brown, pellucid- 

 punctate all over ; these whitish dots gathered in irregular patches, 

 changing their contour with the animal's motions; when it was 

 closely contracted, an open network of dark lines appeared all 

 over the surface. Out of water, the whitish patches confer a 

 general glaucescence upon a dull brown ground. The animal is 

 tinted, especially behind, with carmine, from the deep lake-colored, 

 viscid, glairy fluid it emits in a stream, apparently at will. Black 

 eye-specks, distinct at the base in front of the posterior pair of 

 tentacles. I have not the means, at present, of identifying the 

 species, which seems to be not at all rare, but presume that it may 

 be recognized by the above description. 



TJtriculus canaliculatus, Say. 



Dredged, and on the beach. 

 Bulla solitaria, Say. 



Dredged. 

 Chiton apiculatus, Say. 



Fragments on the beach, and one perfect specimen, dredged. 

 Entails pliocena, T. & H. 



Numerous specimens, all dead; beach, and dredged. 

 Crepidula fornicata, Linn. 



Yery abundant, and the one oftenest found alive ; one, or several 

 together, upon the outside of other larger shells. 



Crepidula fornicata, var. intorta, Say. 



Several specimens.' 



[July 25, 



