138 



5 — 14 rows of zooecia in the separate segments. The radical fibres spring from a 

 pore-chamber in the proximal part of the marginal zocecia. In the older part of 

 the colony they form a Hat bundle on the basal surface, immediately within 

 each lateral margin, with oblique transverse connections at the base of the sep- 

 arate segments. 



The colonies examined originate from ('ape Town. 



Menipea Laniouroux. 



It will be evident from the above summary of the genera that the genus 

 Menipea like the genus Heteroflustni is only negatively characterized, as it com- 

 prises all the species that cannot be referred to any of the other genera. 



M. roborata Hi neks, 

 Membranipora roborata Hincks, Annals Nat. Hist. ser. 5. Vol. VIIl, 1881, 



pag. 128, PI. 2, fig. 3. 

 Flustra membraniporides Busk, Challenger, Zoology, Vol. X, pars 1, pag. 54, 



PI. XXXII, fig. 7. 

 Flabellaris roborata Waters, Journ. Linnean Soc, Zoology, Vol. XXVI, 1898, 

 pag. 672, PI. 48, figs. 10—11; PI. 49, figs. 7 — 11. 

 (PL II, figs. 7 a-7 k.) 

 The zooecia long, hexagonal or hexagonally vase-shaped, often with an acutely 

 projecting corner between the distal and the proximal part. The gymnocyst is 

 very slightly developed on the zocrcia with no avicularia (e. g. some marginal 

 zott'cia) and may on those with avicularia occupy about one-fourth of the whole 

 length of the zooecium. In the entire periphery of the frontal area a distinct, 

 granular cryptocyst is seen, deeply immersed and strongly developed especially 

 at the proximal end, and attaining its highest development in the marginal zoav 

 cia. There may be four spines distally. The two central ones are very small and 

 bud-shaped, but often wanting, while the other two are rather short, as a rule 

 present, but often wanting in the marginal zocrcia. The marginal zocrcia, which 

 are larger but rarely longer than the other zoa'cia, are very asymmetrical and 

 their obliquely oulbending lateral wall has a straight or slightly convex frontal 

 margin. On isolating a row of zoa?cia after boiling in caustic potash it will 

 easily be seen thai the inner surface of the zooecia (figs. 7 d — 7 h) has a some- 

 what varying number of solid calcareous processes of dilTerent length and thick- 

 ness, of which generally 1 — 4 may be seen through each lateral surface. In many 

 zooecia a larger or smaller part of such a calcareous process may protrude on 



