142 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 4 



cave, the abcauHne, convex, so that the margin is nearly horizontal; 

 margin with three teeth, the one on the adcauline side is low and blunt, 

 the other two, sharper; operculum of three flaps. 



Gonosome. — Not observed. 



Note. — This species has a hydrotheca and a hydrothecal arrangement 

 resembling that of S. quadrifida Hartlaub but the habitus is quite unlike 

 that of this species. 



Aglaophenia prominens, new species 

 Plate 21, Fig. 12 



Trophosome. — Colony (terminal fragment 20 mm.) slender, with 

 hydrocladia up to 2.5 mm. in length, and at the most ten hydrothecae. 

 Nodes of the stem oblique but usually indistinct. Hydrocladia alternate, 

 those of the two sides making an angle of approximately 120° with each 

 other; nodes of the hydrocladia readily visible but not very pronounced. 

 The hydrotheca occupies practically the whole length of the internode, 

 but is attached for only approximately the basal third ; the remainder 

 stands out distinctly and the separation is greater just next to the attach- 

 ment. There are no distinct transverse septal ridges but there is a pro- 

 nounced ridge running up from the base, near the face, to mark off the 

 mesial nematophore. There are nine teeth on the margin; the median 

 tooth, not recurved, is very similar to the one on each side of it, leach 

 deeply cut and sharply pointed; there is a large rounded indentation 

 between the first and second laterals, the second tooth being also 

 rounded; the third and fourth pairs are also rounded, the third being 

 less than the second and the fourth less than the third. The mesial 

 nematophore is short, far from reaching to the margin of the hydrotheca 

 and projecting but little; the supracalycine nematophores are short, 

 scarcely reaching the margin. 



Gonosome. — The corbula is short and stout, with six pairs of leaves. 

 There is one hydrotheca between the corbula and the base of the hydro- 

 cladium. 



Plumularia micronema, new species 

 Plate 21, Fig. 13 



Trophosome. — Colony 35 mm., slender, unbranched or loosely and 

 irregularly branched; stem divided into regular internodes by trans- 

 verse nodes. Each internode bears a hydrocladium near the distal end, 

 the hydrocladia alternating right and left in the same plane. The proxi- 



