372 BUI.I.ETIN OF THE BUREAU OF FISHERIES. 



Scandia mutabilis (Ritchie). 



Campanularia mutabilis Ritchie, Hydroids from Cape Verde Islands, 1907, p. 504. 

 Lafaea magna Warren, Natal Hydroids, 1908, p. 342. 



Trophosome. — Colony creeping, giving off single individuals at fairly regular intervals; pedicels 

 short but varying somewhat in length, strongly annulated, the annulations having a spiral arrangement; 

 hydrothecas large, with flaring rim, often placed obliquely and sometimes reduplicated; shallow corru- 

 gations sometimes present; diaphragm narrow but readily distinguishable; proboscis dome-shaped. 



Gonosome. — Gonangia borne on the stolon, with shorter pedicels than are usually found for the 

 hydrothecae, oval in shape; the male much the same shape and size as the hydrothecEe, the female 

 longer and more slender, more or less corrugated; truncate, with the opening much smaller than the 

 whole upper surface. 



The gonosome has not been described hitherto. 



Distribution. — On Aglaophenia rigida and Aglaopkenia minuta and occasionally directly on the 

 sargassum to which these plumularians were attached; on the seaward side of Bogue Bank. 



Family SERTULARID^. 



Trophosome. — Hydrotheca? sessile, arranged on both sides of the stem and branches and more or 

 less adnate to them; hydranths with conical proboscis. 



Gonosome. — Gonophores producing sporosacs, never free medusae. 



Key to the Genera of Sertularid.e Found in the Beaufort Region. 



A. Hydrothecas in opposite pairs. 



a. One pair of hydrothecse to each intemode Sertularia. 



b. Hydrothecse arranged in groups of pairs Pasyihea. 



B. Hydrothecs alternate. 



a. Operculum with one abcauline flap or two flaps Thuiaria. 



b. Operculum with three or four flaps Sertularella. 



Genus PASYTHEA. 



Trophosome. — H)'drothec3e opposite, arranged in groups of two or more pairs, the different pairs of 

 each group being luiequal in size ; margin with two or three teeth; operculum usually with two flaps. 

 Gonosome. — Gonangia oval with large aperture. 



Pasyfhea quadridentata (Ellis and Solander). 



Sertularia quadridentata E. & S., Nat. Hist. Zooph., 1786, p. 57. 



Pasythea quadridentata Bale, Australian Hydroid Zoophytes, 1SS4, p. iij. Bale, Proc. Linn. Soc. N. S. W., 2d ser., in, 1888, 



p. 770. Nutting, American Hydroids. pt. n, 1904, p. 75. 

 Pasythea nodosa Harfitt, Biological Bulletin, 1908. p. 114, 



Trophosome. — Colony usually from 3 to 8 mm. in height, but sometimes reaching 20 mm.; stem 

 unbranched or slightly branched, arising from a creeping stolon, divided into quite regular nodes, 

 bearing from one to five pairs of hydrothecae; nodes rimning obliquely from front to back. Commonly, 

 the first intemode has one pair of hydrothecae and all the others have more than one pair; three pairs 

 are the commonest in the Beaufort specimens. The hydrothecae of the lowest pair are bent out nearly 

 at right angles, the next pair less so, and the distal pair adhere for the greater part of their length. 

 The members of each pair are united in front, but are some distance apart behind. Most of the colonies 

 have but two, three, or four internodes, but one specimen with as many as 13 was obtained. The 

 margin of tlie hydrotlieca has two or three teeth. 



