OF ARTS AND SCIENCES. 149 



Ctenophorac, as there are peculiar tubes for each row of combs, 

 for the netting apparatus, for the stomach, for the mouth, and 

 for the ocular bulb. He further showed that the walls of the 

 digestive and circulating cavities are cellular, like the other 

 parts of the body, and that the gelatinous mass itself is^ divid- 

 ed into large cells by partitions similar to the hyaline mem- 

 brane of the vitreous body of the eye. He also illustrated 

 the various modes of development of these animals, and de- 

 scribed the successive changes of their alternative generations 

 in the Tiaropsis diademata ; the embryo of which he has seen 

 escape from the ovary, move about free for some time, and 

 finally attach itself and grow into a polyp-like animal with 

 tentacles, the first stage of growth of a Campanularia, which 

 is its other mode of existence. He finally enumerated the 

 species of Ctenophora3 and naked-eyed Discophorag which he 

 has observed in Boston Bay, referring them to the modern 

 genera to which they belong, viz. Pleurohi'acJda rhododactyla^ 

 Bolina alita, StauropJiora laciniosa, Bougainvillea superci- 

 liarisj Sarsia mirabilis, and IHaropsis diademata, pointing 

 out the differences by which they are distinguished from the 

 species already described, and the generic characteristics of the 

 new type he has recognized among them. The discovery of a 

 new species of Staurophora on these shores is a new instance 

 of the remarkable analogy which exists between the fauna of 

 the Atlantic States and that of the northeastern shores of Asia. 

 Dr. B. A. Gould made some remarks on the comet now vis- 

 ible, which had passed remarkably near the earth during the 

 last week. He had, however, in spite of this near approach, 

 heard of but two observers who had seen it with the naked 

 eye, namely, Mr. Bond, in Cambridge, and a gentleman in 

 Salem. 



" The first rough elements deduced from observation, within two 

 days after its discovery, were so strikingly similar to those deduced by 

 Bessel {Berliner Astronomisches Jahrluch, 1809, p. 99) from Klink- 

 enberg's observations of the second comet of 1748, as to lead to 

 strong suspicion of the identity of those two bodies. The following 



