THE PLUMULARID./E. 17 



diameter of the oeinatophore, while iu Cladocarpu* i/ramiin tliey bave long, wiuglike, lateral 

 expansions (tig. 2S). In Lytovnrpus philippmus they are long and tubular. In L. rlarlti-i they 

 have two openings, one terminal and one iutero-lateral (fig. 67). In L. fur cat us they are forked, 

 each fork terminating in a round opening (fig. 68). In the genus Kirehenpaueria the supraealycine 

 nematophores are entirely lacking; and in Pentandra (von Leudeufeld) there are two pairs of 

 supraealycine nematophores, as the term is used in this -work, which, iu connection with the 

 mesial ncmatophore, make five of these structures associated with each hydrotheca. According 

 to von Lendcnfeld's figure (fig. 74),' all of these are bithalamic. 



The mesial nematophores are always present in the Statoplea, being usually more or less 

 adnate to the front of the hydrotheca, and are never very distant from it. In several species of 

 Cladocarpus they are distinctly separate from the hydrotheca, while in others they are very short 

 and aduate. In some other species, for example, Lytoi-arpus ramosiis, they are adnate to the entire 

 front, while in others, for example, Halicornaria longicauda (fig. 73), they are aduate to the entire 

 front and project far beyond and above the hydrotheca. In most species the basal portion of the 

 mesial ueiuatophore is adnate, while the distal end is free in the form of a short spur (Lytocarpm 

 fitrcattts) or it may be a lengthened hornlike process as in llalicornaria illc'mtoma Bale. A rare 

 arrangement is illustrated by Thccocarpus bcnedicti (Plate XXV, fig. 3;, which has two mesial 

 nematophores in the median line below each hydrotheca, and a unique arrangement is found in 

 AglaopJienopsis h h-mtta where the nematophore is so broadly forked as to appear iu frout view to be 

 double (lig. 64). Another unique form is represented in the "double-barreled" mesial nematophore 

 of Ar/laophcnia bicornuta (fig. 55). There is much diversity also in the apertures of the mesial 

 nematophores. Where they are short, or are not adnate to the hydrotheca, they are furnished 

 with a single aperture which may be terminal and round (Cladocarpus carinatus, fig. 02), 

 or terminal and posterior that is, facing the hydrotheca as in Thecocarpits nonnani. In 

 Aglaophenopsis this is the case with each part of the forked nematophore, but here the margin is 

 finely denticulate. So far as I am aware, there is no Cladocarpus in which this nematophore has 

 two external openings, either both internal, or one external and the other leading into the 

 hydrotheca. In many species of Aijlttophenia there is a terminal opening which is, of course, 

 external, and also an orifice connecting the adnate portion of the nematophore with the interior of 

 the hydrotheca, for example, A. lopliocnrpa (fig. 53); in others of the same genus there appear to 

 be three openings, one at the distal end, another, external, above and near the junction of the 

 nematophore with the hydrotheca, and the third, internal, connecting the aduate portion of the 

 nematophore with the hydrothecal cavity as iu Aglaophcnid minutn (fig. 51). 



In a number of species of Halicornaria (for example, II. longicauda) with very long mesial 

 nematophores these structures have two distinct external openings, one terminal, and the other just 

 above and fronting the hydrothecal aperture (fig. 73). Mr. Bale, iu a letter to the author, says: 

 "I have noticed iu llalicornaria longirostris that occasionally iu parts of the polypidom the 

 terminal aperture is wanting, the nematophore being closed at the end, but I imagine that this is 

 temporary or abnormal." 



The cauline nematophores are ordinarily small, spurlike processes with a terminal opening, 

 aduate by their inner sides to the stem, the aperture being broad and oblique, partially facing the 

 stem (fig. 57). They also communicate by a broad opening with the cueuosarc of the stem. One 

 or two of these structures are almost always to be found at the base of each hydrocladium on the 

 an tero lateral aspect of the stem and branches. In addition to these there is often a single 

 nematophore on the frout of each internode near its lower end. In the nonhydrocladiate part of 

 the stem they sometimes occur in a linear series, for example, Cladocarpus pectiniferus, and where 

 the stein is fascicled they may occur in numerous series, each corresponding to one of the 

 component tubes of the stem, for example, Thecocarpus (Aglaophenia) myriophyllum and Thecocarpus 

 benedicti. 



The principal variations in six.e and shape of cauliue nematophores among the American 

 species of Statoplea are illustrated by the accompanying figures, all of which are drawn to the 

 same scale with the exception of fig. (50. A typical form would be that found iu fig. 57, from which 

 the principal departures are, first, a constricted orifice (tig. 59), with a tendency to a separation of 



' The Australian Hydromedusu.-, Pt. 4, Proceedings of the Liunean Society of New South Wales, IX, Pt. 3, 1884, pi. xvi. 

 12833 2 



