NEW HYDROIDS — FRASER 579 



EUPERISIPHONIA RIGIDA, new species 



Plate 33, Figure 7 



Trophosome. — Colony consisting of a straight, rigid, fascicled 

 stem (largest fragment 3.5 cm.) and stiff, straight branches given 

 off in subopposite pairs, almost at right angles to the stem. The 

 axial tube is slender, with hydrothecae arranged in regular alter- 

 nation, Hydrotheca on a short pedicel, tubular, with a sharp curve, 

 so that the distal portion is almost at right angles to the proximal 

 portion, with a distinct perisarcal thickening in the concavity; the 

 basal portion, at least one-half, is adherent to the stem, from which 

 it is readily separated by immersion in hot, weak potash solution. 

 There may be one or two reduplications of the margin, which is 

 entire. There is a nematophore on each pedicel, near the base of 

 the hydrotheca. 



The peripheral tubes are more numerous in the proximal portion 

 of both stem and branches, but they do not disappear entirely even 

 at the tips of the branches; they bear no hydrothecae, but the long, 

 slender nematophores are numerous. 



Gonosome. — Unknown. 



Ty^e.— U.S.N.M. No. 43439. Taken by the United States Fish- 

 eries steamer Albatross in Yucatan channel, latitude 20°59'30''' N., 

 longitude 86°23'45'' W., 130 fathoms, January 22, 1885. 



Genus DIPHASIA Agassiz 



? DIPHASIA CRASSA, new species 

 Plate 33, Figube 8 



Trophosome. — Stem heavy and coarse, rigid, and straight, divided 

 into regular internodes by transverse nodes; each internode with a 

 proximal pair of opposite hydrothecae, then an opposite pair of 

 branches, followed by two opposite pairs of hydrothecae. Branches 

 given off in opposite pairs from the stem are slenderer than the stem 

 but still stiff and rigid; constrictions between the pairs of hydro- 

 thecae form rather indefinite nodes. Hydrothecae opposite, although 

 there may be a single one at the proximal end of the branch, cylin- 

 drical, curved slightly outward, adnate for the greater part of their 

 length; margin entire or very slightly sinuous, sometimes with re- 

 duplications; operculum delicate, of one adculine flap. 



Gonosome. — Unknown. 



2"y^e._U.S.N.M. No. 43440. Taken by the United States Fish- 

 eries steamer Albatross, southwest coast of Chile, latitude 51°12' S., 

 longitude 74°13'30'' W., 258 fathoms, February 6, 1888. 



