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tentacles, covered with a pavement of lasso-cells for their whole 

 length, as in the club of the long tentacles ; and the third kind of ten- 

 tacle, which is always found at the base of the Hydrocysts, as Huxley 

 calls them, are perfectly simple, thread-like appendages, with an oc- 

 casional cluster of lasso-cells like small warts. From the observations 

 Mr. Agassiz had made about the development of this genus, he was 

 incHned to believe that the Hydrocysts became separated, — that a float 

 was formed at the extremity which was formerly attached. Below 

 this float, swimming bells, deckstiicke, tentacles, Hydrse, soon made 

 their appearance, and thus young were formed, precisely in the 

 same way as those which were developed from the eggs. Although 

 he had never seen them separate, yet he had frequently found Hydro- 

 cysts still attached with strong constrictions at the base, in which an 

 oil bubble had become separated into a distinct cavity by the folding 

 of the walls. These Hydrocysts, thus attached, could in no way be dis- 

 tinguished from young specimens which were found floating about, 

 and which afterwards developed in confinement to adult specimens. 

 Hence strong probability that by the separation of these Hydrocysts 

 we have in Physophoridte a mode of development similar to the bud- 

 ding of some genera of Hydroids, in addition to the development by 

 sexual reproduction. In jars in which adult specimens had been 

 placed these Hydrocysts were frequently found after they had sepa- 

 rated. On account of their small size they may however have escaped 

 notice at first, and been introduced with the adults. This species is 

 quite small, never growing to more than two or three inches. Speci- 

 mens of that size had the reproductive organs quite well developed. 

 This species appears to be nocturnal, as not a single specimen was 

 ever taken during the daytime : scarcely a night passed while fishing 

 for them without finding several. He would propose for this species the 

 name of Nanomia cara. It is found at Nahant during the summer 

 and fall. This is the first free Hydroid found north of Cape Cod, 

 and, if we except the occasional washing ashore on the Cape of speci- 

 mens of Physalia arethusa TU., brought by the gulf stream, the only 

 species known to inhabit the coast of New England. A more detailed 

 account of this interesting Hydroid, with figures and its embryology, 

 will shortly be published. 



On motion of Dr. A. A. Gould it was voted that the names 

 of all persons who have contributed toward the erection of 

 the new building the sum of one hundred dollars and up- 

 wards, be entered on the Records of the Society as Patrons. 



Mr. Thomas MacFarlane, of Acton Vale, C. E., was elected 

 Corresponding Member. 



