36 McMURRICH. [Vou. III. 
the long and the short pairs alternating, the former only being 
perfect. The mesogloea is exceedingly delicate. Longitudinal 
muscles, moderately strong (PI. III., Fig. 14), are developed on 
all the mesenteries, as well as a very weak parieto-basilar. All 
(including the directives?) are gonophoric. The specimen ex- 
amined was a female, and the number of ova present seemed 
very great. From this description it will be seen that the 
arrangement of the mesenteries is very different from what 
occurs in Offhiodiscus, in which the first three cycles, two of 
which are perfect, alone possess longitudinal muscles and are not 
gonophoric, the reproductive organs being limited to the non- 
muscular mesenteries of the fourth cycle. These differences, 
taken with others which have already been pointed out, seem to 
justify a separation of the two genera into distinct families ; 
but, as already remarked, such a separation is as yet hardly 
necessary. 
Sub-tribe STICHODACTYLINE 
= Family Stichodactyline, Andres, 1883. 
Hexactiniz, in which some of the interseptal spaces com- 
municate with more than one tentacle, the latter being thus 
arranged in radial series encroaching upon the central portion 
of the disc. The tentacles are in some cases all of one form, 
z.e. tentacular, and in other cases are of two forms, some being 
tentacular and some frondose or of varying form. Base ad- 
herent. 
Family Discosomide. 
Synon. — Discostominz — Verrill, 1868. 
Discosomide (pars) — Klunzinger, 1877. 
Discosomidz — Andres, 1883. 
Stichodactylinze, with tentacles of only one form, short and 
tentacular, and covering the greater portion of the surface of 
the disc. Sphincter muscle strong and circumscribed. 
This family as here limited agrees with Andres’ sub-family of 
the same title. The term employed by Verrill owes its origin 
to the proposed change of the name of the principal genus 
Discosoma. 
