82 AMERICAN HYDROIDS. 



DIPLOPTERON QUADRICORNE, new species. 

 (Plate XV, tigs. 6,7.) 



Trophosome. Colony of fragmentary specimen ;m unbranchod stem, attaining' a height of 

 about one-half inch; stem not fascicled, with distant and very oblique nodal joints; hydrocladia 

 alternate, springing from the front of the stem, directed forward and not divided into regular 

 interuodes, there being, however, a few very distant and ill-defined constrictions, and one well- 

 defined proximal iuternode without a hydrotheca and separated from the rest of the hydrocladium 

 by a very oblique node. Hydrotheea- separated by a little more than their own height, one and one- 

 half times as high as wide, conical, adherent to the hydrocladia throughout; margin circular and 

 entire; there is a hydrotheca on the stem at the base of each hydrocladium; a pair of very long 

 lateral nematophores borne on a long process from the stem a little below the top of the hydro- 

 theca; another pair of supracalyeinc nematophores just above the first, but not borne on distinct 

 processes; two or three mesial nematophores between adjacent hydrotheca'.; cauline nematophores 

 of unusual length scattered irregularly over the front of the stem. 



Gonosome. Not known. 



Distribution. Dredged near Habana, Cuba; depth, 150 to 200 fathoms; State University of 

 Iowa, Bahama expedition. 



Nearly all of the greatly elongated lower pairs of lateral nematophores were broken off in the 

 specimen secured, but a few were fortunately still attached and proved to be considerably longer 

 than the hydrotheca' and exceedingly slender, with a small, trumpet-shaped enlargement at the 

 distal end. 



Type slides. Vat. No. 11703, Mus. State Univ. Iowa; Cat. No. 18580, U.S.N.M. 



DIPLOPTERON GRANDE, new species. 

 (Plate XVI, figs. 1,2.) 



Trophosomc. Colony attaining a height of 14 inches, unbrauched; stem fascicled; hydrocladia 

 alternate, borne on the front of the stem and attaining a length of 2 inches, divided into irregular 

 iuternodes, the nodes being distinct on the proximal part and becoming obliterated toward the 

 distal end. Hydrotheca^ very large, deep, closely approximated; anterior outline doubly curved 

 like the front of a pitcher, margin entire, not cut away posteriorly; a hydrotheca at the base 

 of each hydrocladium; a pair of nematophores borne on processes opposite the middle of each 

 hydrotheca; another pair on very slight processes on a level with the top of the hydrotheca, and 

 a third pair between the second and the base of the next hydrotheca above; cauline uematophores 

 scattered along the front of the stem. 



Gonosome. Gonangia borne on accessory ramuli springing from the hydrocladia and composed 

 of three branches, each armed with numerous nematophores and bearing an occasional hydrotheca. 

 The gouangia are ovate, with the terminal aperture surrounded by a slight rim or collar, and are 

 borne in clusters of three to six on each hydrocladium. 



Distribution. Albatross Station 2667, lat. N. 30 53', long. W. 79 42' 30", 273 fathoms; Station 

 2668, lat. N. 30 59', long. W. 79 39',. 294 fathoms; Station 2671, lat. N. 31 20', long. W. 79 22', 

 280 fathoms. 



This species is closely allied to 7>. hnr/ipinna, but can at once be distinguished by its immense 

 hydrotheca', which are among the largest of the Eleutheroplea and have a very characteristic out- 

 line when viewed from the side. The accessory ramulus, which 1 regard as essentially a phylacto- 

 goniuin, is more highly modified than in other species in which it occurs, the hydrotheca^ being 

 sometimes absent except at the bifurcations of the ramulus, where a single one is constantly found. 



Type slides. Cat. Nos. 18582, 18583, U.S.N.M.; Cat.Nos. 11706, 11708, Mus. State Univ. Iowa; 

 also in the collection of the author. 



