NEW SPECIES OF HYDROIDS — ERASER 87 



AGLAOPHENIA TRANSITIONIS. new species 



Plate IS, Figube 14 



Tropohosome. — Colony with a long, somewhat rigid main axis, 8 cm., 

 a limited number of branches given off from the distal half of the 

 stem; each branch leaves the stem in the same manner as a hydro- 

 cladium, but after it has given rise to seven or eight hydrothecae it 

 definitely becomes a branch and gives off hydrocladia similar to those 

 from the main stem. The hydrocladia are relatively short (maximum 

 4 mm.) and arise alternately from the face of the stem, so that the 

 supporting processes form a zigzag row, but slightly curved; divided 

 into regular short internodes by distinct nodes, so that the hydrothecae 

 are closely placed ; the hydrotheca is little longer than broad and is 

 stouter distally than proximally, adnate throughout almost the whole 

 length ; margin with 11 teeth ; the median tooth is erect or very slightly 

 retrorse, sharp, smaller than the tooth on each side; the tooth next 

 to the median on each side is the longest, the second one is the smallest, 

 and the third, fourth, and fifth are nearly equal ; all of them are rather 

 sharply pointed. There is no definite anterior intrathecal ridge ; the 

 posterior is strongly marked but does not reach far. 



The supracalycine nematophores, which do not nearly reach the 

 margin of the hydrotheca, are strongly curved, so that the opening 

 points backward : mesial nematophore not prominent, projecting from 

 the hydrotheca in the distal third of its anterior surface. Of the three 

 cauline nematophores that on the hydrocladial process and the one 

 below the insertion of this process are tubular; the one near the axil, 

 i. e., distal to the process, is triangular and larger than either of the 

 others. 



Gonosome. — Not observed. 



Type.—V.^.^M. No. 43458. Taken by the United States Fisheries 

 steamer Alhatross at station 3150, latitude 37°47' N.. longitude 

 122°44'10'' W., off Golden Gate, Calif., 21 fathoms. 



Genus PLUMULARIA Lamarck (in part) 



PLUMULARIA POLYNEMA, new species 



Plate 18, Figure Id 



Trophosome. — Stem simple, slender (from fragment 83 mm. long), 

 divided into regular internodes with well-marked nodes, each bearing 

 a single hydrocladium on a prominent process near the distal end. 

 All the internodes in the hydrocladium are long, slender, and thecate, 

 except that in some instances an extra nonthecate internode appears, 

 making an intermediate internode, with two nematophores, and a 

 thecate internode that is much shorter than the others, with but one 



