287 
the Sertulariidae. " But Hartlaub!) has also found a blind sack 
im the campanularian genus Silicularia,.and I have: found it in 
Lictorella pinnata Sars. It is also found in the operculate species 
described as Zygophylax operculata Jåd. (Pl. IV, fig. 21) and Lyg- 
grandis Vanh.?), and I cannot doubt but. that it is also present as well 
in the inoperculate species related to them as in the other species 
of the genus Lictorella. ; The presence of the blind sack in the 
named. cases, therefore, seems ,to be contingent upon the more or 
less eres bilateral; symmetry. 
;. Campenhausen who also refers Grammaria to the Ser- 
tulariidae says about my reference of "Synthecium and the other 
above named forms to the, Lafozidae?): »Abgesehen aber davon 
dass die erwåhnten' Formen s0 typisch alle iibrigen Sertularien- 
Charactere bezitzen ausser diesen einen .,... und,mir ..... eine 
Trennung nur auf ein Merkmal hin willkirlich vorkommt, scheint 
mir das Vorhandensein oder der Mangel eines Operculums -durchaus 
nicht [von so einschneidender Bedeutung zu sein.” As v. Cam- 
penhausen does not seem to ascribe systematic .significance to. 
the arrangement of the hydrothecæ, the typical sertularian -characters, 
about which he speaks, must be the bilateral symmetrical structure 
of the hydrothecae, and the more' or less extensive connection 
between their adcauline wall and the corresponding axial structures"). 
ÅS to the first named character there is no contrast between the 
named. forms and the other Lafoéidae, as most members of this 
family and especially of its freely: branched forms, show a more or 
less distinct bilateral symmetry, which is found not only in species 
with sessile or adnate »hydrothecae, but sometimes also in such 
species the hydrothéeæ of which are provided. with. free stalks. 
3 10 12, note 
| ed v. Batousikraest regards the presence of a well-developed 
aphragm as a specific sertularian character, I may here point out 
I: the diaphragm is quite lacking or imperfectly developed in a 
number of Sertularella-species. ; 
