191 



they are either eyeless or there remain but one pair in some 

 species, in others a few, on some of the joints. 



Terebella fulgida,of which Prof. Agassiz exhibited a drawing, 

 had been supposed heretofore to be eyeless. He had recently 

 obtained specimens at various stages of growth with eyes, the 

 number diminishing as the animal approached maturity. Cirra- 

 tulus, of which he exhibited a figure, he had found to be an 

 immature Terebella. The branchial appendages characterizing 

 it disappear with its development. He had thus been led to the 

 conclusion, at variance with the commonly received opinion, 

 that the abranchiate Annelids are the highest type of that class. 

 Hsematorhosa, of which Prof. Agassiz exhibited a drawing, has 

 very long tentacles, and is filled with blood free in the cavity of 

 the body. It has no blood vessels. The blood is made to accu- 

 mulate at different points, sometimes bulging out the body at one 

 place, sometimes at another, or distending the tentacles ; thus 

 giving a variety of shapes to the animal. This species, which is 

 quite abundant under the stones on the Beach at East Boston, is 

 highly phosphorescent, emitting brilliant sparks when irritated. 

 Its power becomes exhausted, but is renewed when the animal 

 " has remained quiet a sufficient length of time. 



Prof. Agassiz also exhibited drawings of four new species 

 of Doris, to which he had given the names diademata, 

 coronata, teneJla, and pallida ; also of Placobranchus, and a 

 new species of Canthopsis, for which he proposes the name 

 C. Harvardiensis ; also of Actseon, a genus never before 

 obtained in America, and which he had found in great 

 numbers in Charles River and the creeks about Cambridge. 

 This animal is of a bright green color, owing to the presence 

 of Chlorophyl, which is soluble in Ether like the Chloro- 

 phyl in plants. Prof. Agassiz^ stated that he had, during 

 the past summer, obtained by dredging off Gay Head, Me- 

 lihcea arbuscula ; a new species to naturalists on this side 

 of the Atlantic, characterized by tentacles like those of Do- 

 ris, and gills like those of Annelids. 



In reply to a question, Prof. Agassiz said that the perma- 

 nent eyes of the Annelids were furnished with transparent 

 media ; those that disappear are merely pigment spots. 



