288 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 4 



Plumularia venusta, new species 

 Plate 42, Fig. 54 



Trophosome. — Colony, 24 mm, is slender, graceful; the stem is di- 

 vided into regular, long internodes, by faint, transverse nodes ; each inter- 

 node gives off a hydrocladium just below the distal node, hence the hydro- 

 cladia are regularly alternate. The hydrocladia are long, up to 5 mm, and 

 slender; the nodes are well marked, and each is flanked on each side by a 

 partial, but well marked, septum. The first internode is short, athecate; 

 all the others are long, thecate; the first thecate is not as long as the 

 others. The hydrotheca is about one-fourth of the length of the internode 

 from its distal end. The athecate internode has no nematophore; the first 

 thecate has 2 mesial nematophores, and each of the others has 3. The sup- 

 racalycine nematophores are of the usual type. There is a nematophore 

 at the axil of the hydrocladial process, and 2 cauline nematophores on the 

 side opposite to the hydrocladial process, on each internode. 



Gonosome. — Not observed. 



Distribution. — Station 579-36, east of San Marcos Island, Gulf of 

 California, 18 fathoms. 



Remarks. — This species is little like any species so far reported from 

 the Eastern Pacific, but it closely resembles P. polynema Fraser, described 

 from near Marthas Vineyard, off the New England coast, although it is 

 not possible, with the information available, to see how any distributional 

 connection can exist between the 2 species. 



P. venusta has not the same mode of growth and arrangement of 

 branches as" P. polynema. In the stem, the nodes are not so strongly 

 marked; in the hydrocladium, there is the small, proximal, athecate inter- 

 node, and the septa are well marked. The nematophores on the hydro- 

 cladium are similarly placed, but there are only 2 cauline nematophores 

 instead of 3 on each internode. The gonosome has not been observed in 

 either species. 



Genus SGHIZOTRICHA 



Schizotricha tenella (Verrill) 

 Plumularia tenella Verrill, Invert. An. Vineyard Sound, 1874, p. 731. 

 Schizotricha tenella Eraser, Hancock Hyd., 1, 1938, p. 67. 



Eraser, Atlantic Hyd., 1944, p. 358. 



Distribution. — Off San Nicolas Island, 28-31 fathoms. 



