AMERICAN HYDROIDS. 105 



Af/Jaophenopsis. It is apparently very close to Clatlorarpiix spei-insus Yerrill, from which it (lifters 

 chiefly iu not having the two anterior marginal teeth more conspicuous than the others, and in 

 having a more cylindrical nydrotheca. 



Type. In the Museum of Comparative Zoology, Cambridge, Massachusetts. 



AGLAOPHENIA BICORNUTA, new species. 

 (Plate XXIV, tigs. 5-8.) 



Trophosome. Colony sparingly branched, attaining a height of about 3 inches; stem not 

 fascicled, divided into regular internodes, each of which bears a bydrocladium on a process from 

 the middle portion of its antero-lateral face; hydrocladia rather distant, alternate, and divided 

 into regular iuternodes without septal ridges. Hydrothectv rather deep, anterior profile slightly 

 concave, margin not greatly everted, and armed with nine prominent, sharp-pointed teeth ; 

 iutrathecal ridge very low, evident, oblique; supracalycine neraatophores small, distinctly genie- 

 ulated, and slightly overtopping the hydrotheca; mesial nematophore double, consisting of two 

 slender tubes placed side by side like the barrels of a shotgun, and pointing forward and a little 

 downward, the free portion being about as long as the hydrotheca is wide; the two tubes are 

 separate and somewhat divergent at their distal ends; cauline uematophores rather large, one on 

 each side of the base of each hydrocladium, and a rnaininillate one on the base of each hydro- 

 cladium. 



Gonosome. Not known. 



Distribution. Oft' EJabana, Cuba, 150 to 250 fathoms, State University of Iowa expedition. 



In the absence of the gonosome this species is only provisionally referred to Aylaoplu'nin. 

 The "double-barreled" mesial uematophore is a unique feature in this genus, the only approach 

 to it being the double mesial uernatophore of Aglaophenopsis himuia, which, however, is entirely 

 separate from the hydrotheca and very short, with crenate apertures. 



Type sliiles. Gut. No. 18664, U.S.N.M.; Cat. No. 15370, Mus. State Univ. Iowa; also in the 

 collection of the author. 



AGLAOPHENIA (?) CONSTRICTA Allman. 

 (Plate XXIV, fi-s. 1-3.) 



Aglauplienia coimtricta ALLMAN, Mem. Mus. Comp. Zool., 1877, V, No. 2, p. 47, pi. xxix. 



Trophosome. Stem attaining a height of about 8 inches, thick, fascicled, springing from an 

 entangled mass of wiry filaments, and sending off numerous, irregularly disposed, simple branches, 

 which carry alternately disposed pinna; (hydrocladia); three pinna- springing from each inter- 

 node. Hydrotheca' with the distal half expanded and separated from the proximal part by a 

 deep constriction ; margin with four broad teeth. Supracalyciue nematophores slightly overtopping 

 the margin of the hydrotheca; mesial nematophore nearly equaling in length the height of the 

 hydrotheca, to which it is almost entirely aduate; cauliue uematophores, two on the axil of each 

 pinna and one immediately below the pinna in front. 1 



(fonosoiiie. Not known. 



Distribution. Off Couch Reef, from a depth of 30 fathoms. 



Although this species almost certainly belongs to another genus, it is here included in the 

 genus Aylaophenia on sufferance, as it were, uutil the gonosome is discovered. 



Type. In the Museum of Comparative Zoology, Cambridge, Massachusetts. 



AGLAOPHENIA TRIFIDA Agassiz. 



Aglaoplienia cristata McCRADY, Gymn. of Charleston Harbor, 1857, p. 100. 



Aglaujihenlu trijlfla Lons AGASSIZ, Cont. Nut. Hist. U.S., 1862, IV, p. 358. 



Aglaopli/'iiia trifula ALEXANDER AGASSIZ, N. A. Aealeph., 1865, p. 140. 



Aglaoplii'nia trilhla KIKCIIKNPAUER, Ueber die Hydroiclenfara. PlumulariiUi', 1872, Pt. 1, p. 26. 



Trophosome. Colony branched, attaining a height of 5 to 7 inches; stem not fascicled, divided 

 into regular short iuternodes, each of which bears a hydrocladium on its middle portion; hydro- 



1 Original description quoted exactly. 



