274 AGALMA. 



as Schneider has pointed out, and even if normal it would indicate merelj- a 

 special arrangement of the bracts. The feature on which Bedot's genus Stephan- 

 opsis is based, namely, that the terminal filaments of the tentilla can be retracted 

 within the involucre, is certainly not of importance equal to that of the essential 

 structure of those organs. Cupulita and Halistemma (Agalmopsis Schneider) 

 are separated by the presence of an involucre in the former, contrasted with 

 its absence in the latter. But the involucre is a secondary structure in develop- 

 ment and its absence therefore is not sufficiently important to necessitate a 

 separate genus; at most it may indicate a subgenus; and certainly the slight 

 difference in the arrangement of the palpons described bj' Chun ('88) and by 

 Schneider ('98) is not more than a specific character. Accordingly two genera, 

 one tricornuate, the other unicornuate are recognized in addition to Anthe- 

 modes and Lychnagalma. 



The earliest undoubtedly tricornuate species is Agalma okeni Eschscholtz 

 ('25), the type of the genus Agalma. The siphosome of a species of the second, 

 unicornuate, genus was described by Peron and Lesueur in 1807 as Stephaiiomia 

 nmphitrides. Fortunately the figure, though schematic and on a small scale, 

 clearly shows that each tentillum has a coiled cnidoband with single terminal fila- 

 ment (this is not to be seen in the copy by Lesson '43, pi. 10, fig. 1, la), and 

 this species, studied later by Huxley, is represented in the present collection. 

 Stephanomia, of course, long antedates both Cupulita, and Halistemma; indeed, 

 it was the first Agalmid described. It must therefore be used for the uni- 

 cornuate genus. 



AGALMA Eschscholtz, 1825. 



Agalma comprises two well-known species which have often been recorded, 

 a third, which has been well described and is quite distinct, but which has been 

 taken very seldom, and a fourth which is of doubtful validity. And, in addi- 

 tion, some of the older descriptions listed below (p. 354) as unrecognizable may 

 belong here. The two well-known Agalmas have usually been known as Cry- 

 stallomia ipohjgonala Dana (Crystallodes rigidus + vitreus Haeckel) and as Agal- 

 mopsis or Agalma elegaris Sars {A. sarsi Kolliker). But, as Schneider has 

 recently shown, the former is in reality Agalma okeni Eschscholtz. Esch- 

 scholtz's figures are so accurate and show so clearly the characteristic "habitus" 

 and the very diagnostic prismatic bracts ('29, pi. 13, fig. 1), that Fewkes long 

 ago proposed this union, and it is surprising that it has not been generally adopted. 



Bedot ('96) seems to have overlooked the importance of the bracts as specific 



