THE PHYSOPHORlDiE. m 



suctorios, vesiculos varise formffi et tentacula offerens. Tentacula sacculis clavalis {clava 

 varice formcB) obsita." 



Sars remarks (p. 40) upon the features which this genus has in common with both the 

 Agalma of Eschscholz and the Steplianomia {Awjihitridis) of Peron, and, indeed, it would 

 be difiBcult to separate it by any character, save that assigned to the tentacula, from 

 Ayulma. If the tentacula really have a " clava varise formae/ A(/almopsis differs not only from 

 Agahna, but from all Physophoridce at present known, except Bhizophysa, whose tentacles, 

 however, are so differently and so much more simply constructed, that they can hardly serve 

 as terms of comparison. 



After a careful study of Sars' memoir, I must confess that I am strongly inclined to 

 believe that his Agalmopsis clegans embraces in reality species of two distinct genera, one 

 a true Agalma, with the tentacles characteristic of that genus, the other a form closely allied 

 to what I have described below as Stejjhanomia, believing it to be the 8. Amphitridis 

 of Peron. 



Sars' " first kind of tentacles " (1. c, tab. v, figs. 5 and 6, p. 35) are, in fact, exactly like 

 those which I have figured in Stephanomia, and unlike those of any other genus of Phgsophorida 

 with which I am acquainted. The '■'Agalmopses," enumerated by Sars at p. 36, under (c), 

 which were the largest, and were taken from the end of November until March, possessed 

 only this one kind of tentacle ; and the most of those taken in autumn, and enumerated 

 under {a) p. 35, had only these, and those peculiar organs whose structure is not very 

 clearly represented in Tab. VI, fig. 10. I suspect these were all StephanomicB. 



The individuals enumerated under {b), taken contemporaneously with the last named, 

 had tentacles exactly like those of Agalma, and tentacles of the first kind, in addition, 

 according to Sars. But with every respect for the accuracy of observation of the justly- 

 esteemed Norwegian naturalist, I think it very possible that he may have overlooked the real 

 mode of termination of the younger tentacles of this form, and have been led to imagine 

 their ends single when they w-ere really trifid. In this case they would all belong to 

 Agalma. 



Whatever be the real nature of the species described by Sars under the head of 

 Agalmopsis, however, there is, as Vogt has justly pointed out, an insuperable objection 

 to the genus, as defined by its author ; the sole distinctive character given by him being 

 accidental, and depending on the extended state of his specimens, whose solid appendao-es 

 would, had they been contracted, have formed a tube, as in Agalma. 



Leuckart (Z. N. K , p. 73), admitting the justice of Vogt's elimination of the genus Agal- 

 mopsis, as defined by Sars, appears, nevertheless, to wish to retain the term, as the designation 

 of that section of Agalma which has naked tentacular sacs, and a long, straight ccenosarc. 

 Unfortunately, in this case, the sub-genus Agalmopisis would not contain either of Sars' 

 species, so that there would be considerable risk of confusion. Under these circumstances, 

 I propose to retain the name Agalma for those species whose tentacular sacs are provided 

 with two filaments and a median lobe, and to give to the Agalma rubrum of Vogt, and its 

 allies, the generic appellation of Ilalisfemma. 



The following systematic arrangement of the Phgsophorida appears to mc to be in 

 accordance with our present knowledge. Under each genus I have given the names of those 

 species which have been carefully examined and may be considered to be established. 



