238 BULLETIN 100, UNITED STATES NATIONAL MUSEUM 



more distinct on the distal than on the proximal parts; but divide 

 internodes of irregular length. Hydrocladia springing from the 

 front of the main stem, but inclined alternately to right and left and 

 are divided into internodes by indistinct nodes, each internode of 

 the main stem bearing a hydrocladium. Hydrothecae cup-shaped, 

 one and one-half times as long as wide, distal part bent somewhat 

 outward and the aperture opening at an angle of about 15° with the 

 axis of the hydrocladium. Marginal teeth vary considerably, but 

 are often more prominent than is usual in this genus, there being 

 two lobe-like or bluntly pointed lateral teeth and a sharply pointed 

 median or front tooth. The anterior intrathecal ridge character- 

 istic of this genus is well marked and proceeds from a strong indenta- 

 tion about half way up the front of the hydrotheca, showing in pro- 

 file as a doubly curved line reaching more than half way across the 

 hydrotheca. Nematophores, supracalycine nematophores roughly 

 triangular in outline, their tops not nearly reaching the level of the 

 top of the hydrotheca and aperture round. Mesial nematophores 

 very narrow, tubular, closely adherent to the front of the hydrotheca 

 almost or quite throughout their length and not reaching the top of 

 the hydrotheca. Their front profile is straight or with a slight 

 double curve. There is a partial septum opposite the intrathecal 

 ridge. 



Gonosome. — Not present. 



Locality. — Dredging station 5251, Gulf of Davao. Linao Point. 

 7° 5' 12" N., 125° 39' 35" E.; depth, 20 fathoms. 



Holotype.— Cat. No. 42186, U.S.N.M. 



This species is nearest my Halicornaria flava from Hawaiian 

 waters or H. ishikawai Stechow from which it differs in the promin- 

 ence of the hydrothecal teeth and the slenderness of the mesial 

 nematophores as well as in certain characters of the stem. 



(?) HALICORNARIA MAGNIROSTRIS, new species 

 Plate 47, figs. 5, 6 



Trophosome. — Colony an aggregation of pinnate stems grow- 

 ing from a creeping root stalk, stem fascicled, hydrocladia alternate, 

 very closely approximated and set on opposite sides of the branch 

 or stem from which they spring; divided into regular hydrothecate 

 internodes and showing intercladial ridges just above the mesial 

 nematophores and two others, one above and one below the supra- 

 calycine pair. Hydrothecae of the usual Halicornaria type with an 

 interior intrathecal ridge and a sharp bay or sinus on its front mar- 

 gin just above where the mesial nematophore becomes free; margin 

 with a rather sharp anterior tooth and two lateral lobular teeth, the 

 hindmost being partially hidden by the supracalycine nematophore. 



