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 zooecia. In the older part of 

 the colony they form a flat 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 Cape Town. 



Menipea Lamouroux. 

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

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

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



M. roborata Hincks, 

 Membranipora roborata Hincks, Annals Nat. Hist. ser. 5. Vol. VIII, 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. 

 (PI. 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 zooecia with no avicularia (e. g. some marginal 

 zooecia) and may on those with avicularia occupy about one-fourth of the whole 

 length of the zooecium. In the entire peariphery 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 zooe- 

 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 zocecia. The marginal zooecia, which 

 are larger but rarely longer than the other zooecia, are very asymmetrical and 

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

 margin. On isolating a row of zocecia after boiling in caustic potash it will 

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

 what varying number of solid calcareous processes of diff"erent 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 



