342 SIR SIDNEY F. HARMER ON 
species. Its detei-miiiation was confirmed when I remounted in Canada 
balsam one of Busk's dry slides (99.7.1.698) oi M. marionensis from Stat. 
142. Fig. 44 has been drawn from Busk's slide thus treated. 
The calcareous spines developed from the cryptocyst are one of the most 
striking features of a Canada balsam preparation of Menipe.a marionensis. 
They are relatively few in young zooecia, in which they are directed towards 
the basal surface (figs. 22, 43, 44). In the older zooecia (fig. 45) they are 
much more numerous, some of them being branched, and some of them being 
directed towards the frontal membrane. These spines appear to be of the 
same nature as the similar structures which have been described by Levinseu 
(1909, p. 138, pi. ii. fig. 7, c-e) in Menipea roborata. As in other members 
■of its familj^ each distal zooecium of Menipea marionensis overlaps its 
predecessor to a considerable extent on its basal surface, as indicated in 
fig. 22. In the older zooecium represented (fig. 45) p is the proximal 4ia\\ 
of the distal zooecium, and the opesia has been restricted by the formation of 
a horizontal calcareous lamina, the free edge of which is in the form of a 
Grothic arch (e) ; while the opesia is further reduced by the enlargement of 
the proximal cryptocyst. 
The remarkable internal avicularia of this species are described above, in 
Sect. III. 
6. Menipea trisbkiata, Busk. (PL 17. fig. 18; PL 19. figs. 40-42.) 
? Crista elegans, Lamouroux, 1821, p. 6, pi. 65. figs. 4-'i . Cape of C4ood Hope. 
Menipea triseriata, Busk, 1852", p. 22, pL 23. figs. 2-4. S. Africa. 
„ „ Busk, 1884, p. 21. Cape of Good Hope. 
„ „ Waters, 1898, J. L. S. zxvi. p. 672, pi. 48. fig. 12. 
Internodes more or less triserial, composed of numerous zooecia. External 
spines 2, internal 2, on outer zooecia ; 1, 1 on median zooecia. Cryptocyst 
strongly developed on the proximal side of the opesia, covered with minute 
iubercles, its free margin here strongly thickened, and usually produced into 
a strong median tooth which may be directed basally. Marginal avicularia 
on most of the zooecia. Frontal avicularia often two on the median zooecia, 
one of which may be replaced by an internal avicularium ; reversed (the 
rostrum directed distally) on the distal side of an ovicell, an arrangement 
commonly found in this genus. The outer frontal avicularium is wanting 
on the marginal zooecia. Ovicells short, usually broader than long. 
The British Museum possesses a number of slides, all from South Africa. 
A specially interesting feature of this genus is the possession of internal 
avicularia (figs. 41, 42), which have been described above, under Sect. III. 
7. Menipea quadeata {Busk). 
Cellulana quadrata, Busk, 1884, p. 18, pi. 6. figs. 5-6 &. Kerguelen, Heard Islanda 
Internodes long and narrow, consisting of numerous zooecia. Spines and 
.frontal avicularia wanting. Marginal avicularia small. 
