328 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



The condition of the margin of the stomach in this species is pre- 

 cisely what it would be in a Pegantha did the sexual products develop 

 irregularly and sparsely near the outer edge of the lower gastric 

 wall instead of being localized in regions where the lower walls grow 

 downward, as pockets, to accommodate them. Apparently Van- 

 hoffen had not seen this species, for he has given the name flavescens 

 to a form with gastric pockets ; that is, a Solmissus. I must confess 

 that I can not understand Vanhoffen's statement (1908, p. 69) that all 

 species of his genus /Solmaris have interradial gelatinous septa hori- 

 zontal to the plane of the stomach, instead of vertical to it, as in 

 Aeginidae. Inasmuch as the gastric pockets in Solmissus marshalli 

 and S. albescens (Bigelow, 1909a/ Mayer, 1910) are structurally pre- 

 cisely similar to the corresponding pockets in Cunina and Cv/noc- 

 tantha, it is in such forms as Solmaris flavescens Kolliker (not S. 

 flavescens Vanhoffen) that we must seek horizontal septa if they 

 exist anywhere. By a horizontal septum must be understood one 

 which, by growing centrad, leaves the lower gastric wall reaching 

 outward beyond, and thus overlapping its line of union with the oral 

 surface of the disk; in other words, forming a horizontal pouch. 

 But there is nothing of this sort in S. flavescens any more than there 

 is in Pegantha, as is clearly shown in Mayer's figure of a section 

 through the interradius (1910, fig. 286). The only thing which 

 might possibly suggest such a septum is the fact that the sexual 

 mass in the male may overlap the subumbrella slightly, beyond the 

 gastric margin. But this is purely a secondary phenomenon, caused 

 by the rapid proliferation of the sexual cells themselves; that is, 

 it is directly comparable to the secondarily formed genital pouches of 

 Pegantha, and has nothing to do with the gastric pockets of Solmissus 

 or Cunina, which develop long before the sexual products begin to 

 appear. 



The genus Solmaris of Vanhoffen includes two distinct groups 

 of species — one with, the other without, gastric pockets. According 

 to the classification proposed by Maas, and here adopted, they not 

 only belong to different genera, Solmaris and Solmissus but to dif- 

 ferent families. 



Two of Vanhoffen's species of Solmaris, his S. flavescens, which, 

 as noted above, is not the Solmaris flavescens of Kolliker, Gegenbaur, 

 and latterly of Mayer (1910), and probably three specimens iden- 

 tified by him as S. rhodoloma Brandt belong to Solmissus, as here 

 defined. 



The present collection contains a considerable series of Solmissus 

 marshalli, a species separable from the well-known Mediterranean 

 S. albescens Gegenbaur only by the lack of exumbrellar sculpture 

 (Mayer 1910), large number of otocysts, and square instead of 

 slightly pentagonal gastric pockets. 



