FLORIDAN BRYOZOA. 11 



Membraniporella Agassizii l ) (Pl. V, figs. 103 — 106), 



taken by Pourtales from a depth of 450 fathoms, off Cojima, Cuba. These specimens 

 are fragments of white-shining, dichotomously divided, cylindrical stems (fig. 106) of a 

 slender Eschara-growth. (auctt.). As they are all broken at both ends, they do not show 

 the mode of fixing of the colonies; but from the tips of the branehes down to their 

 lower parts, very completely, they present the changes of the species with age. The 

 young zooecia (fig. 103) precisely agree with Membraniporella nitida, except that the 

 ribs are narrower and usually more numerous (12 — 8 pairs). The avicularia, which in 

 that species either wanted or were irregularly scattered in the interstices between the 

 zooecia, here, with the same form 2 ), take a greater development and a constant place, 

 pointing distally, one at each side of the mouth of the zooscia. The ocecia are rounded, 

 with a transverse rib, discontinuous in the middle, forraing the margin of their aper- 

 ture. Their wall is ornamented by two or three pairs of transverse ribs, converging 

 towards a longitudinal area on their front, thus repeating the construction of the late- 

 ral wall (outside the area) of the zooecia 3 ). On the older parts of the stem, the in- 

 terstices between the area? of the zooecia cover themselves with rounded warts 4 ) (figs. 

 104 and 105), crowned by a circular area, which is circumscribed by a rib, from which 

 transverse ribs descend, in the same manner as just described on the ooecia. As these 

 warts are augmenting in number, they take a more irregular shape, heaping themselves 

 densely together, not only över the lateral parts of the zooecia (fig. 104), but also 

 covering the proximal part of their area? (fig. 105), and so going on until the whole 

 front side of the zooecia is overgrown. At the same time, this new covering of the 

 stem takes the avicularia with it, leaving them irregularly dispersed on its glossy, warty 

 surface. 



As to the size of this species, I have measured the mouth (operculum) of a zoce- 

 cion with a breadth of about 0,n> mm. 



Although I place this species here, among the Membraniporidce, we shall have to 

 consider it again, when we are discussing the affmities of the Eschariporidce. 



Very near to the lineata-series, within the Membraniporidan family, another one 

 also is to be arranged 5 ), with the Membranipora Flemingii, Busk, as the best known 

 type. As the principal character for the group, thus formed, I may cite the v/ords of 

 Busk, in his description of one of the species 6 ): "Aperture sub-trifoliate, or somewhat 



1 ) Compare the Escharipora filiformis, D'Orb., Pal. Franc, Terr. Gret., vol. V, pag. 232, tab. 700, figs. 13 — 15. 



2 ) Compare Krit. Fört., 1. c, tab. XX, fig. 50. 



3 ) The drawer has omitted these markings on the zooecia (fig. 103) but for a figure of them, I can refer 

 to a comparison with Krit. Fört., 1. c., pl. XX, fig. 22, where the same markings are shown on the sides 

 of a Zfzta-zooscion. 



4 ) Compare Hippothoa (Lepralia) Brogniartii, Busk, Uat. Brit. Mus., Pohjz., p. 65, pl. LXXXI, fig. 1. 



This speeies I refer to the genus Hippothoa, although its characteristic, as yet known, rather will place 

 it into the Escharidan family. Still, in that family, we do'nt know any relatives to it; and the median 

 sinus, otherwise the most constant character of the Myriozoids, which here wants, in the Hippothoa hyalina, 

 also, is wanting in those zooecia, which produce an ooecion at their tip. 



ä ) Krit. Fört. etc, Öfvers. Vet. Akad. Förh. 1867, pag. 367, 403 etc. 



6 ) Quart. Journ. Micr. Se, vol. VI, pag. 262. 



