PERIPHYLLOPSIS. 27 



height previously collected by the " Albatross " in the Pacific, including 

 those recorded by Mayer (: 06) from the Hawaiian Islands. 



The only large Periphylla taken during the expedition was alive, and 

 swam vigorously by pulsations of the bell when placed in an aquarium jar. 

 So far as the pigmentation is concerned, it is a typical P. hyacinthina, the pe- 

 ripheral canal system being so densely pigmented that no trace of the gonads 

 can be seen from without. In outline, however, it more nearly resembles P. 

 dodecabostrycha, the proportion of height to diameter being only about 1.1 : 1. 

 Moreover, the bell is much less pointed than Vanhoffen (: 02", taf. 2, fig. 9) 

 has represented it, a condition already noted by Maas (: 04", p. 47) for a 

 specimen collected by the Prince of Monaco. After watching the alternate 

 contractions and expansions of the living specimen, I feel sure that small 

 differences in the form of the bell are to be regarded merely as due to different 

 degrees of contraction. As has often been described for the species, the 

 present specimen shows an apical projection of the stomach into the meso- 

 gloea. But that the presence of this structure is good evidence that Peri- 

 phylla passes through an attached scyphistoma stage seems to me very 

 doubtful. The general color, which is that characteristic of the genus, is 

 very well represented in Vanhoffen's figure. 



The three small specimens from Stations 4652 and 4669 would be referred 

 to P. dodecabostrycha if the latter were recognized as a separate species from 

 P. hjacintlihia. Tlie measurements of the two better-preserved specimens 

 are about 4 mm. high by 8 mm. in diameter, both being somewhat flattened. 

 None of them show any trace of gonads. They are in all respects typical 

 P. dodecabostrycha, having the low bell and the endodermal pigment wholly 

 restricted to the central stomach, as is characteristic of that form. 



I have reproduced, in PI. 9, fig. 2, a colored sketch made from the 

 fresh specimen to illustrate more fully this limited pigmentation. It is 

 interesting to observe that although the peripheral canal system is entirely 

 hyaline, the rhopalia are pigmented. The ring muscle is already well 

 developed, as are the pedalia, and the ring furrow is deeply marked. 

 Unfortunately all three are too much battered to determine whether a " Stiel- 

 canal" was present, a question of great interest in such small specimens. 



Periphyllopsis Vanhoffen, 1902. 

 Periphyllinae with four sense organs, 5X4 tentacles and 6X4 marginal 

 lappets. 



