HALITREPHES. 145 



ture of the tentacles is that typical of the family, the differentiation into 

 proximal and distal regions being well marked. 



Both of the specimens are entirely colorless ; Maas's specimen, on 

 the other hand, had the gonads and entire entodermal system heavily 

 pigmented. 



Homoeonema species ? 



Plate 34, Figs. 4, 6, 7. 



The collection contains a single very small specimen of this genus, taken 

 at Station 4676, 300 fathoms to surface, too young for specific identification. 

 A general oral view of this individual is shown in the photograph (PI. 34, 

 fig. 6). In outline the bell is flat, the gelatinous substance thin. In diam- 

 eter it measures 7.5 mm., a size at which H. alba already has ten to twelve 

 tentacles per octant. There are very few tentacles, the numbers per 

 octant being 3, 2, 3, 3, 3, 3, 4, 3. In the octants in which there are three 

 there is an interradial tentacle flanked on either side by a very rudimentary 

 ad radial one. Structurally the tentacles differ from those of adults of this 

 genus, in that they do not show any differentiation into two regions, but 

 are soft and flexible throughout their entire length. There is a single 

 otocyst, of the typical halicreid form, in each octant (PI. 34, fig. 4). 



The stomach is flat, mouth open, radial canals broad (PI. 34, fig. 6) ; two 

 of the latter unite at their bases. 



There is as yet no trace of gonads. 



Color. — In life, the entire entodermic system was of a pale orange tint. 



Halitrephes, gen. nov. 



Halicreasidae with numerous (twenty-eight) radial canals; without ex- 

 umbral papillae. 



This genus is proposed to contain a new species which on account of 

 the structure of tentacles and otocysts, the breadth of the radial canals, 

 and conformation of the gastric cavity, undoubtedly belongs to the Hali- 

 creasidae, but which differs from all other members of the family in having 

 a large number of radial canals. The general appearance is so much 

 like that of Aequorea that, until I examined the marginal organs, I be- 

 lieved that it belonged to that genus. I take pleasure in naming the one 

 species after Prof. Otto Maas, in recognition of the valuable results of 

 his studies on this family. 



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