PROCEEDINGS OF SOCIETIES. 65 
Dr. E. Perceval Wright exhibited the dental apparatus in 
situ of a tubicolar Annelid, which in all probability is the 
Nereis tubicola (O. F. Miiller), as described in ‘ Zoologia 
Danica,’ but which does not belong to the genus Onuphis (Milne- 
Edwards). The teeth are like those commonly met with in that 
section of the family Eunicea distinguished by having teeth, and 
they consist of a pair of sickle-shaped and three pairs of serrated 
horny teeth, in addition to a pair of well-developed teeth con- 
taining carbonate of lime. 
Dr. John Barker showed fine examples from a copious gathering 
made in the Pheenix Park of the always beautiful Volvox globator. 
Mr. Archer wished, while Volvox was before the meeting, to 
mention that he had lately made some observations on the ame- 
boid condition of the gonidia of this organism, largely confirming 
Dr. Hicks’s interesting statements. 
Mr. Archer then exhibited fine and beautiful fresh examples of 
Mougeotia glyptosperma (de Bary) in every stage of conjugation, from 
the first approach of the parent filaments up to the fully formed 
and remarkably grooved zygospore. He showed de Bary’s figure 
of this plant (‘ Untersuchungen iiber die Familie der Conjugaten,’ 
t. viii, figs. 20, 21, 22, 23, 24, 25); also living conjugated examples 
of Mesocarpus parvulus and M. scalaris, in order to draw attention 
to the distinctions between Mougeotia glyptosperma and the latter 
—distinctions surely correctly regarded by de Bary as of generic 
value. This plant, as accurately identified, must be called new to 
Britain ; but it is not impossible that it may have been before met 
with, and recorded under the name of Mesocarpus intricatus ; but 
Mr. Archer had never seen authentic specimens of the plant known 
by the authorities under the latter name. Professor de Bary does 
not himself seem to have seen living examples of his Moug. 
glyptosperma, as his descriptions are drawn up from dried speci- 
mens from Professor Alex. Braun’s herbarium ; therefore it would 
seem asif this plant must be accounted rare. But the present 
remarkably pretty plant, as De Bary well points out (loc. cit.), is 
not truly a Mesocarpus, but in its mode of conjugation more 
nearly approaches certain Zygnemata, Ina systematic point of 
view, it presents double affinities, but it is nevertheless per se at 
once readily and unmistakably distinct, especially when seen 
conjugated. It is, no doubt, related, on the one hand, to Meso- 
carpus (Hass.); like it, the endochrome forms a compressed lon- 
gitudinal band, and like it, too, the zygospore is formed half-way 
between the two conjugating joints. But it is distinguished 
strongly by the fact that here the whole cell-contents, “ primordial 
utricles” and all, of the two conjugating joints, completely coa- 
lesce, leaving the old cell-walls wholly empty, in order to form the 
zygospore ; whilst in Mesocarpus the contact of the “ primordial 
utricles” of the two conjugating cells is not followed by a complete 
coalescence of the two into the zygospore, but, by a concentration 
of the principal part of the green and solid contents in the con- 
VOL, VI.—-NEW SER. F 
