PANDEA VIOLACEA. 205 



I agree with Hartlaub ('92) and Maas (: 04 c ) that the conformation of the 

 sexual organs is sufficiently divergent in these three to warrant their reten- 

 tion as separate genera. To express the confusion which reigns within 

 these genera I cannot do better than quote the following words of Maas : — 

 "il est impossible de demeler dans l'etat present de nos connaissances les 

 especes differentes decrites sous les synonymes divers ( Oceania incl.) et, cer- 

 tainement en plusieurs cas, la meme espece se trouve cataloguee dans des 

 genres differents" (: 04°, p. 12). The present collection contains specimens 

 referable to Pandea, Tiara, and Turris, the latter apparently representing 

 a new species. 



Pandea Lesson, 18.'i7. 



sens. em. Haeckel ('79). 



Tiaridae with horseshoe-shaped gonads, not transversely folded, and 

 only slightly interrupted in the perradii. 



Pandea Violacea Agassiz and Mayer. 

 Pandea violacea Agassiz and Mayer, '99, p. 160 ; Mayer, : 00'', p. 34, pi. 1, fig. 1. 



Plate 41, figs. 10, 11. 



Acapulco Harbor; surface; 7 specimens, all about 4 mm. in diameter 

 by 4 mm. high. 



These specimens differ from the Fiji examples described by Agassiz and 

 Mayer ('99) and those from the Tortugas described by Mayer (: 00 b ) in 

 having a smaller number of rudimentary tentacles. In each there are eight 

 well-developed tentacles, extensible to a length greater than the height of the 

 bell (Mayer, : 00 b , p. 34), though usually strongly contracted. In addition, the 

 present specimens have only eight rudimentary tentacles, alternating with 

 the well-developed ones, while in Mayer's specimens there were twenty-four 

 of these. This difference appears, however, to be one of development, not of 

 species, since in the regular course of the formation of additional rudimentary 

 tentacles the next stage would be that found by Mayer. Mayer merely says 

 of the gonads that they distend the proximal part of the manubrium; and 

 inasmuch as he figures them as simple ovate perradial swellings it seems (hat 

 he overlooked their essentially interradial nature ; this can be clearly traced 

 in the present specimens, for though at first sight the gonads look like radial 

 structures, closer examination shows that there is no break in the formation 



