THE SERTULAKID^E. 105 



This very peculiar species is with doubt referred to the genus X/ /////<//, Ra. I take pleasure 

 in naming it in honor of Doctor Hartlaub, who has done more than any other one man to bring 

 order out of chaos in this very perplexing genus. 



Type slides. Cat No. 19760, U.S.N.M.; Cat. No. 18705, Museum State University of 

 Iowa; also in the collection of the author. 



?SERTULARELLA NANA Hartlaub. 



(Plate XXVI, tig. 0.) 

 Sertulardla nana HABTLAUB, Hydroiden aus dem Stillen Ocean, 1901, p. 361. 



Trophosome. Colony unbranched (fragmentary), about 5 mm. high. Stem not fascicled, 

 slender, divided into irregular internodes Toy usually distant nodes, proximal hydrothecate nodes 

 smooth, short, not sharply separated from each other; the following internodes longer, bearing 

 as many as four hydrotheciv. Hydrotheca' lying in one plane, alternate, inserted below the 

 internodes, deep, distal portions strongly narrowing and gracefully curved, with convex adcau- 

 line side, base somewhat swollen; margin with two teeth, or perfectly smooth, in which case the 

 aperture is beveled so as to be nearly vertical; operculum present. 



Gonnxome. Not known. 



DtKti'ilnifiii/i. Found growing on LafoSa t/r<t<-iUiintt at Bare Island, Puget Sound. 



I have not seen this species, and have drawn the above description from that of the original 

 describer. It is almost certain that it is not a X, /////<//< //it, and would probably go more prop- 

 erly in TJuiiaria, as used in this work. I do not feel justified in disturbing its position, however, 

 without more evidence. 



Type. In the collection of Professor Schauinsland? 



DICTYOCLADIUM Allman. 



Trophosome. Colony flabellate in form. Branches anastomosing and forming a rudely 

 reticulate structure or network. Hydrotheca? on more than two sides of the stem. Aperture 

 without conspicuous teeth. Operculum variable. 



Gonosome. Gonangia borne in the bifurcations of the branches and marked with annular 

 rugosities. 



This genus was instituted by Allman to accommodate one of the many new types secured 

 by the < 'lull, m/er. ' It was also recognized by Marktanuer-Turncretscher.- although at that 

 time but a single species was known. The one herein described shows more evident relation- 

 ship to the genus .SV rt/i/t ircllii than did the original type dredged by the ('/mil, n</, /, especiallv 

 in the operculum. which is essentially of the Sertula/retta pattern. Allman makes no mention 

 of this structure, but it is plainly evident in D. tfal>Jl un^ being composed of four distinct naps, 

 although the teeth are so small as hardly to be evident, being represented merely by four corners 

 to the margin which have the structural effect of low teeth. 



DICTYOCLADIUM FLABELLUM, new species. 

 (Plate XXVIII, figs. 1-3.) 



Trophosome. Colony flabellate in form, attaining a Height of about 4 inches and branching 1 

 in a strictly dichotomous manner; few evident internodes on stem or branches, the onlv annu- 

 lations or constrictions ordinarily being tho.se at the origins of branches or branchlets. 

 Branches straight, not flexuose, themselves dichotomously branching in the same plane, the 

 ultimate branches often anastomosing with other branches, forming a rude reticulate pattern. 



Hydrotheca 1 arranged in four longitudinal series on stem and branches, so as to form an 

 ascending spiral, tubular, about the distal one-third free, curved gently outward, margin 



' Challenger Reports. The Hydn.id:i 1't. 1', 1SS8, p 76. 



2 Hydroiden des k. k. naturhistorischen Hol'museums, 1890, p. 219. 



