266 BULLETIN OF THE 



its axis the peduncles are retracted and the bracts are pressed closely together 

 in order to ofler less resistance to the direct advance of the animaL 



The greatest care must be taken in transferring the colony from its native 

 element into aquaria, otherwise it will drop all its nectocalyces and the l)racts 

 will fall off, their attachment to the colony is of such a fragile nature. Sfe^j/ia- 

 nomia is much more delicate than most other genera of Physophores. 



Agalma papillosum, sp. nov. 



Plate V. Figs. 5, 6. Plate VI. Fig. 37. 



The genus Agalma* Esch., is represented by at least two species in Florida 

 seas. One of these is A. eler/ans, which is also found in Narragansett Bay. 

 The other is a new species, A. papillosum, of which two immature specimens 

 were found near Key West, Florida. 



A papillosum resembles A. elcgans in many particulars of structure, and might 

 be mistaken for it. There is, however, this important difference between the 

 two American species of the genus. 



The most important characteristic of A. papiillosum is the presence, on the 

 outer surface of the covering-scales and upon the swimming-bells, of short 

 papillaj, swollen at their extremities into spherical knobs (PL V. figs. 5, 6). 

 As far as I have studied other genera of Physophores there are none where 

 similar appendages are found on these parts. 



The axis of the specimens taken was very short, and seemed to indicate an 

 immature animal. A single feeding polyp Q') is found hanging from the end 

 of the stem, and several tastern {d d! d") could be seen protruded between the 

 covering-scales (c). The float («) is large, thickly pigmented at its apex with 

 crimson spots. It has a small aperture communicating between its air-sac 

 (a a) and the surrounding medium. 



The nectocalyces were all immature and few in number. The largest 

 swimming-bell (n) was about half grown, as its relative size seemed to indi- 

 cate, and is shown, as seen from above, on Plate V. fig. 6. In most particulars 

 of internal structure the swimming-bells resemble the young nectocalyces of 



* I include in the genus Agalma those long-stemmed Pliysophores with a biserial 

 arrangement of the nectocalyces and tentacular knobs, composed of a coiled sacculus, 

 covered by an involucrum, and terminated by a vesicle and two lateral filaments. 

 (Eschscholtz, Oken's Isis, 1825, L, and System der Aealephen, p. 150.) For a dis- 

 cussion of the limits of the genera Agalma, Agnlmopsis, and HaUstcmma, see Bull. 

 Mus. Comp. Zool., Vl. 7, p. 132. 



Sars evidently had two or three genera of Physophores which he called Agalmopsis 

 eleganx. One of the.se may have been my Agalma elcgans (Fauna Littoralis Norvegioe, 

 pp. 32-44, Taf. 5, 6). The fu'st form described by him had a tentacular knob like 

 Halisfevima ruhrum, with a well-developed involucrum, which is wanting in HaU- 

 stcmma, Huxley. Such a knob is not very unlike that of Agalmopsis Tcrgestinum 

 and A. gracile. 



