414 Rev. A. D. Sloan on the 



carried forward in the form of a slender axis terminates in the 

 float or pneumatophore. The siphosome constitutes the 

 greater part of the creature and consists of an elongated 

 flexible axis bearing at intervals the bracts, polypes with 

 tentacles, mouthless polypes without tentacles, and various 

 urn-like structures and clusters, which appear to represent the 

 excretory and reproductive organs. Thenectosomeor portion 

 of the axis which bears the swimming-apparatus terminates 

 in a large oval float or pneumatophore, whose anterior wall 

 contains a great deal of reddish pigment. In the Agalmidae 

 the float is described as being very small in comparison with 

 the swimming-bells ; but in this form it is proportionally 

 large, being about three times larger than the largest 

 swimming-bell. The comparatively large size of the float 

 cannot altogether be attributed to contraction of the other parts 

 during preservation, as it is noticeable in a rough sketch made 

 by Mr. Holt when the creature was still alive. 



Behind the float the nectosome presents the appearance of 

 a narrow delicate cylinder, devoid of lateral structures, and 

 extending about two and a half times the length of the long 

 axis of the pneumatophore. It is quite straight throughout 

 all its length, and in it Mr. Holt figures several little bubbles 

 or globules, which are, however, not seen in the preserved 

 specimen. The length of this stalk is comparatively great ; 

 but it is very contractile, and may have been fixed in its 

 extended state. 



This narrow stalk passes somewhat suddenly into a thicker 

 portion of the axis, along which the swimming- bells (necto- 

 calyces, nectophores) are distributed, and which exhibits a 

 spiral twist. At the place where the narrower joins the 

 thicker portion of the nectosome is a small cluster of buds, 

 which represent young swimming-bells. In the specimen 

 may be seen three or four very small buds and then two rows 

 of four buds each, which are continuous with two rows of 

 functional swimming-bells. The buds increase in size as we 

 proceed distally along the axis, and so do the fully developed 

 nectocalyces, the distal ones being the largest. 



The functional swimming-bells consist of a large bell- 

 shaped portion variously compressed and a short pedicle by 

 which they are connected to the axis. They are six in 

 number, arranged in two rows of three. Behind the necto- 

 calyces is a portion of the nectosome devoid of structures, but 

 presenting several little knobs, which may represent the stalks 

 of nectocalyces whose bells have fallen off. 



The nectosome passes into the siphosome or polyp-bearing 

 part of the axis, along which the protective, nutritive, excre- 



