136 
THE VOYAGE OF H.M.S. CHALLENGER. 
(2) Flustramorphci hastigera, n. sp. \ (PL XXL fig. 7). 
IPorellina ciliata, Smitt, Florid. Bryoz., p. 26, pi. vi. figs. 126-129. 
Character . — Zoarium ramose, branches short, ligulate, expanding at the ends, dicho- 
tomous. Zooecia broad ovate, very convex, surface granular. Mouth semicircular, lower 
border straight, entire ; peristome slightly thickened ; three or four oral spines above, 
(often absent). The lunate pore close below the mouth. An 
aviculario-vibracular organ on one side, the basal part of the 
mandible triangular, the apex being turned up at a right angle 
and produced into a spear-shaped acute flagellum. 
Habitat . — Station 75, lat. 38° 38' N., long. 28° 28' W., 450 
fathoms, volcanic mud. 
In the general character of the zooecia this form very closely 
resembles Microporella ciliata, and even in the vibraculoid char- 
Fl ^ra 4 °T^^rcuTu^ C 6, man-" ac f er of the avicularium, a close correspondence in some respects 
dlble- exists, for in the latter species the acute mandible of the lateral 
avicularium, as noticed by Mr. Hincks, “ is often prolonged into a slender vibraculoid 
spine or process.” And in like manner in Flustramorpha hastigera what might be 
termed the triangular mandible turns up at the apex, and is produced into a beautiful 
spear-shaped blade of considerable length, whilst the horizontal basal part forms a fork 
by which it is articulated and furnished with muscles, in such a way as to admit of motion 
only in one plane, and to be shut down upon the rostral portion of the avicularium. 
Precisely the same conditions obtain in Flustramorpha flabellaris, Bk., and Flustra- 
morpha patagonica, n. sp. ? except that in those two forms, as in Microporella ciliata, the 
flagelliform prolongation is not turned up so abruptly. It is curious to remark that this 
appendage is almost exactly like that of the anterior immoveable spine of Lepralia, 
spathulifera, Smitt. In all these cases, therefore, this form of flagellum is apparently 
adapted only for defensive purposes. 
§ 6. Crustaceous. 
2. Microporella, Hincks. 
Microporella (pars), Hincks, 1877. 
Cellepora (pars), Linn.; Andouin. 
Lepralia (pars), Johnst.; Busk, &c. 
Escharina (pars), Milne-Edw.; Gray. 
Herentia (sp.), Gray. 
Reptoporina (pars), D’Orbigny. 
Porina , Porellina, Smitt. 
Character . — Zoarium erect and bilaminar, or encrusting and adnate. Mouth semi- 
