OCR Text |
Show 48 ZOOLOGICAL COLLECTIONS M A D E DURING [J fig. 142), from Florida and perhaps also the Pacific. Prof. Smitt evidently merely placed the species under Hippothoa provisionally. It comes near to the present species, differing from it in the apparently orbicular outline of the secondary orifice, and in the position of the lateral avicularia (of which only one may be present) at the lower end of the peristomial prolongation, and in the smoothness of the peristome. It should therefore stand as Gigantoporafenestrata, Smitt. The present new species is a beautiful and striking form ; the hyaline character of the shell, the curiously dumbbell-like outline of the large front pore (which is apparently its normal form, though it shows great variations from this, being almost orbicular hi some cases) with its distinct rim, the bilabiate aperture of the secondary orifice, and the slender upwardly-projecting vibracula, all give it a remarkable appearance. The question of affinity is a difficult one. The pore differs from that of Anarthropora ; and Smittia, which has a similar peristomial lip, wants the special pore ; while Microporella, on the other hand, has the pore, but wants the lip. Probably the pore is a character of much deeper importance than the lip, derived, as Smitt has shown it, by the example of Porellina {Lepralia) ciliata, to be, from the infra-oral sinus. Therefore perhaps it is best to refer it to the Micropo-rellida? rather than to the Escharidce, with which, however, it would seem to have some points of affinity. PORINA GALEATA, Busk. Lepralia galeata, Busk, Cat. Polyz. Mus. Brit. ii. p. 66, pi. xciv. figs. 1, 2. Hab. Elizabeth Island, Straits of Magellan, 6 fathoms, on thin sea-weed; Sandy Point, 7-10 fathoms, on Pecten-yahe. SCHIZOPORELLA MARSUPIUM, Macgillivray. (Plate VI. fig. 6.) Lepralia marsupium, Macgillivray, Tr. Phil. Inst. Victoria, pt. i. vol. ix. p. 136. Zoarium incrusting; cells adnate, radiating in more or less straight lines from a centre. Zocecia distinct, convex, separated by thin raised lines ; broad, with sharp inferior lateral angles, rounded above, hyaline ; surface glistening, very minutely punctate, and also bearing about 12 very shallow and indistinct pits of small size, scattered. Orifice semilunar, rounded above, with sharp inferior angles, lower lip straight, sinus shallow, rectangular ; from 2 to 3 blunt spines round orifice. Below orifice a very distinctly circumscribed semilunar area, entirely occupied by a large and very prominent avicularian rostrum, convex immediately below mouth; opening large, circular, partially visible from above. Ovicell small, subglobular, minutely punctate, hyaline and glistening, marked by concentric lines. One specimen. Hab. Elizabeth Island, 6 fathoms, on thin seaweed. |