400 MR. HANCOCK ON THE ANATOMY OF THE FRESHWATER 
which the heart is pulmonic, and the breathing organ pharyngeal. 
The reality of this relationship is revealed by the anatomy of 
the Lancelet, so ably described by Professor John Goodsir, who 
has pointed out the resemblance of its respiratory system to that 
of the Z’unicata. Indeed the branchial sac and vascular apparatus 
of this curious fish almost completely resemble those organs in 
the Ascidian. 
The other branch of the Bryozoa, comprising those with oral 
arms, passes into the Brachiopoda ; or, at least, this is rendered 
more than probable by the resemblance of the brachial organs of 
the latter to the arms of the former, and by the similarity of the 
muscular arrangement. Thus the Bryozoa become related to the 
Lamellibranchiata, which are apparently closely related to the 
Brachiopoda. We may conclude, then, if we have arrived at a 
right understanding of the affinities of these animals, that both 
the Mollusca and Vertebrata are connected with the Bryozoa. 
It would be well, therefore, to pause before including the Bryozoa 
in the Mollusca, and consider the propriety of uniting the former 
with the Zunicata, and perhaps with some of the higher forms of 
Rotifera, into a group to be placed at the head of the Radiata. 
DESCRIPTIONS OF NEW SPECIES. 
Plumatella punctata. Pl. VI. figs. 6 & 7, and PI. IV. fig. 1. 
Polypidom adhering throughout, coriaceous, pellucid, of a pale 
watery green colour, irregularly but not much branched, seldom 
extending more than half an inch; branches composed of a series 
of large, eonical cells tapering upwards towards the aperture, 
sometimes considerably and rather suddenly dilated at the base ; 
resembling in form some of the Ascidians ; the upper portion of 
the cell almost colourless and freckled with minute opake white 
spots, most crowded towards the orifice. ‘Tentacles white, not 
more than sixty in number; membrane, at their origin, rather 
wide, scalloped, the points of the scallop extending for some dis- 
tance up the back of the tentacles, in the form of broadish lamine 
arched outwards. Cisophagus and stomach appearing through 
