NO. 5 FRASER : HYDROIDS 245 



These corrugations are almost as much pronounced as they are in S. or- 

 nata Fraser, where the hydrotheca is much smaller. It would appear that 

 S. similis is a recent derivative of S. conica, as it appears within the range 

 of that species, but without the gonangium it is not wise to be too definite 

 in the matter. 



Sertularella sinuosa, new species 

 Plate 28, Fig. 20 



Trophosome. — The colony is small, growing from a non-reticulate 

 stolon, unbranched, slender, with a maximum height of 20 mm, usually 

 much less than this. The stem is sinuous, divided into regular, short inter- 

 nodes which are slightly oblique, or directly transverse. The hydrothecae 

 are strictly alternate, nearly tubular, but slightly turgid in the proximal 

 portion, turned outward to such an extent that the distal half is almost at 

 right angles with the stem; margin with 3 well-marked, sharp teeth, 

 much like those of S. tricuspidata (Alder) ; operculum of 3 flaps. Like 

 the stem, the hydrothecae are small, 0.5 x 0.16 mm. 



Gonosome. — The gonangium arises from the aperture of the proximal 

 hydrothecae, there may be 2 on the one stem; it is large, as much as 1.6 

 mm in length, obovate or elliptical, smooth, with a short pedicel extend- 

 ing from the aperture of the hydrotheca. 



Distribution. — OH San Pedro, Calif., depth not given; %. mile east 

 of South Point, Santa Rosa Island, 17-20 fathoms; 2J4 miles east of 

 South Point, 23-28 fathoms; 2^^ miles east of South Point, 17-18 fath- 

 oms; 3 miles east of South Point, 17-20 fathoms; 4.6 miles SW^W of 

 East Point, 40 fathoms ; 4>4 miles NE of Sandy Point, 35-36 fathoms ; 1 

 mile SE of Smugglers Cove, Santa Cruz Island, 15-21 fathoms; % mile 

 SE of Cat Rock, Anacapa Island, 23-25 fathoms; Laguna Beach, low 

 tide ; 1 mile NW of White Cove, Santa Catalina Island, 2-3 fathoms ; off 

 San Nicolas Island, 30 fathoms; west of Dutch Harbor, 8-9 fathoms; 

 Tanner Bank, 25-28 fathoms; 2^ miles off Point Loma, 9-13 fathoms; 

 South Bay, Cedros Island, 10-15 fathoms; 4 miles north of Dewey Chan- 

 nel, Lower Calif., 24-25 fathoms ; Dewey Channel, opposite San Eugenic 

 Point, 21-24 fathoms. 



Remarks. — This species has a habitus much similar to that of S. tur- 

 gida, but the stem is much more slender and correspondingly less rigid 

 than in that species. The species must be considered as aberrant in that 

 the gonangium arises through the aperture of the hydrotheca, in which 

 respect it resembles those in the genus Synthecium. It is possible that it 

 should be placed in a new genus. 



