618 The Siphonophores. [ September, 
family are found in our waters; these genera may be known as 
Agalma and Agalmopsis. 
A popular description of the latter of these animals was given 
by Mrs. Agassiz in the well-known “ Seaside Studies in Natural 
History” under the name of Nanomia? 
The present article will be devoted to the anatomy of Agalma, 
as I consider it the most typical representative of the tubular jelly 
fishes which have a float. I hope to follow this paper with another 
on the embryology of the same genus. Both articles are outline 
sketches of the subjects of which they treat. 
The word Agalma is of Greek derivation, and means simply 
an ornament. No doubt Eschscholtz, the pioneer in the study of 
jelly fishes had in mind an ornament for the neck when he gave 
this name to the animal. As it gracefully floats in the water with 
its long pendant tentacles hanging behind it, the likeness toa 
living necklace with rosy band and transparent beads is very 
great. It also resembles closely a long, transparent, crystalline 
prism through which passes a highly colored thread resembling a 
longitudinal axis, such as is often found in glass models of 
crystals used in the study of mineralogy. 
It will be found immediately, if one tries to raise the Agalma 
out of the water by the hand, that the prism is not a simple crys- 
talline body, but is formed of members which are joined together 
in such a fragile manner that an attempt of this kind detaches all 
the component parts, and the beautiful crystal falls back into its . 
native element broken into a hundred fragments. The parts thus 
detached are commonly known as individuals, and the whole 
prism as a colony, The individuals or pieces which compose the 
colony are extremely transparent, so that one can with difficulty 
follow by means of the eye their bounding lines, and often times 
to convince himself where the outline is, the sense of touch must 
supplement that of sight; even then one only becomes conscious 
that he has touched the animal when it shrinks away from the 
finger or contracts itself as if alarmed. 
1 Our Agalma, which I think is the same as Sars’ Aga/mopsis elegans, Was discov- 
ered by me while at work in the laboratory of Mr. Alex. Agassiz at Newport. My 
reasons for considering Vanomia a synonym of Aga/mopsis and not Halistemma or 
Stephanomia were given in a paper pubjished in the Bulletin of the Museum of 
Comparative Zodlogy at Cambridge. 
* Nanomia was first described by Mr. Alexander Agassiz. Pioc. Boston So. Nat. 
Hist., IX, p. 181, 1863. See also North American Acalephz, p. 2C0. 
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