388 Dr. J. Barrois on the 
adult male examples. Some of the outlines of the orbits are drawn 
slightly foreshortened on account of the convexity of the dorsal surface 
of the carapace. The character of the stridulating-ridges will be better 
made out if examined with a lens, 
Figs. 1, 1a. Ocypoda ceratophthalma (Pallas). 
Figs. 2, 2a. O. macrocera, Milne-Edwards. 
Fig. 26. Outer view of smaller chela of the same species, showing the 
somewhat dilated fingers. 
Figs. 3, 3a. O. egyptiaca, Gerstacker, 
Figs. 4, 4a. O. rotundata, sp. un. 
Figs. 5, 5a. O. platytarsis, Milne-Kdwards. 
Figs. 6, 6a. O. Gaudichaudi, Milne-Edwards and Lucas. 
Figs. 7,7 a. O. arenaria (Catesby). 
Fig. 76. Under surface of part of first ambulatory leg of the same species, 
showing the long marginal hairs. 
Figs. 8, 8a. O. Kuhlii, De Haan. 
Fig. 8b. Under surface of part of the first ambulatory leg (from a speci- 
men from Cape St. Lucas designated by Stimpson O. occidentalis). 
Figs. 9,9 a. O. cordimana, Desmarest. 
XLI.—Embryogeny of the Bryozoa ; an Attempt at a General 
Theory of their Development, founded upon the Study of thetr 
Metamorphoses. By Dr. JuLES BARROIS. 
[Concluded from p. 279.] 
V. CYCLOSTOMATA. 
My recent researches upon the Cyclostomata, which were 
undertaken specially with the object of studying the pheno- 
mena of the metamorphosis, were all carried on in the Medi- 
terranean, which is so rich in various forms of Cyclostomata, 
and more particularly at Villafranca. The two principal 
types to which I have paid attention are the Frondiporee and 
the Discopore ; the former, remarkable for the large size of 
the larva, which is peculiarly well adapted for observation, 
and with which it is easy to obtain sections, are unfortunately 
difficult to obtain in great abundance. ‘The latter are common 
at Villafranca about the wet dock: their larvee are small, and 
only moderately well fitted for the study of the fixation; but 
they have the advantage of belonging to a type which closely 
approaches the type of the Chilostomata, and may serve per- 
fectly as a means of comparing together the larve of these 
two great groups. Those of the Frondipore do not differ at 
all from the ordinary type that I have already described. 
