118 



THE PLUMULAR1D.E. 



AGLAOPHENOPSIS Fewkes (modified). 



Aglaophenopsis FEWKES, Bull. Mus. Comp. Zool., 1881, VIII, No. 7, i>. 132. 



Trophosome.Stem usually fascicled; hydrocladia with numerous internal septal ridges; 

 hydrothecal margin toothed; iiematophores with creimlated margins. 



Qonosome. Gouangia protected by special appendages growing from the proximal joint of 

 the hydrocladia, and apparently of the nature of greatly modified mesial nematophores of the 

 proximal hydrothecae. 



As originally defined, this genus was further characterized by the fact that the gouophores 

 are never borne on the hydrocladia, and that the protective appendages are jointed and 

 unbranched. Further discoveries, however, have made it necessary to modify the generic defini- 

 tion in order to accommodate new forms. Bale 1 as usual seizes upon the truly salient character 

 of the group, which is the fact that the protective structure pertaining to the gouosome is an 

 appendage of the hydrocladium in the shape of a greatly modified mesial nematophore. 



It must be confessed that the genus as here defined is a rather heterogeneous group, which 

 will probably require further modification. The protective appendage may be simple or branched, 

 with or without hydrotheca' on its distal end. In one species, .4. himuta, the appendage is 

 unbranched, usually without a distally placed hydrotheca, but sometimes with one. In cornnta 

 and rerrilli the appendage is branched, each branch bearing one or more hydrotheca-. In cor- 

 nuta there is a hydrotheca in the axis of each of these secondary branchlets, while in rerrilli 

 there is a gouangium in the same position. In all of the species that I have examined the hydro- 

 cladia are furnished with numerous septal ridges, and the netnatophores have crenulated margins. 



Distribution of American species of the genus Aglaophenopsis. 



KEY TO AMERICAN SPECIES OF THE GENUS AGLAOPHENOPSIS. 



Mesial nematophore double A. hirsuta. 



Mesial nematophore small, separate from hydrotheca 



A prominent auterior tooth on margin of hydrotheca A, distant. 



Marginal teeth subi'qual I. rerrilli. 



Mesial nematophore large, a widely expanded keel to hydrotheca I. cornnta. 



AGLAOPHENOPSIS HIRSUTA Fewkes. 



(Plate XXIX, figs. 8-13.) 

 Aglaophenopsis hirsiita FEWKES, Bull. Mus. Comp. Zool., 1881, VIII, No. 7, p. 133. 



Trophosome. Colony consisting of one to three main upright branches, which give off alter- 

 nate hydrocladia-bearing brauchlets, which may themselves again divide into hydrocladiate ram- 

 uli; height of colony, 8 to 10 inches; stem fascicled, the auterior tube giving off the hydrocladia; 

 hydrocladia sinuous, divided into iuternodes which are regularly curved, the profile of the poste- 

 rior side of the internode being convex opposite the hydrotheca; cavity of each internode divided 

 by numerous septal ridges, which occur not only behind the hydrotheca, but in those portions of 

 the internode between the hydrotheca'. Hydrotheca rather distant, deep, tubular, those on the 

 proximal part of the hydrocladium with their upper third bent slightly forward and free from the 



'The Genera of the Plumulariidss, 1886, p. 16. 



