746 PROCEEDINGS OF THE NATIONAL MUSEUM. vouxxi. 



of dots; the reduplication of margins is not so extensive as in many 

 Halecidte, there being sehlom more than two to each hydranth. 



Ilydranth Lirge, nonretractile, with a somewhat slender, slightly 

 gibbous body and about twenty tentacles. 



Gonosome. —Not known. 



This species is the only one icnown to me among the Halecida- in 

 Avhich the parasitic habit has so profoundly modified the manner of 

 growth that all regularity in branching has been lost. It resembles 

 somewhat the Haloikenui lanhasterii^ Bourne- in this respect, but the 

 latter species is not stated to be parasitic and appears to be rather a 

 very simple, sparingly branched form. The complete annulations of 

 the pedicels is also a novel feature. 



Locality. — Puget iSound, Collected by the Young Naturalists' Soci- 

 ety in 1.895, The specimens were found growing on Sertularella tri- 

 cuspidata. 



HYDRALLMANIA DISTANS, new species. 



(Plate LXIII, figs. 3 A-D.) 



Trophosome. — Stem long, slender, flexuous; cauline internodes long, 

 nonhydrothecate, each giving forth a branch just above its proximal 

 end; branches alternate, hydrothecate, divided into internodes consid- 

 erably shorter than tliose of the main stem, each internode givirig ori- 

 gin to an ultimate branchlet or liydrocladium. Ilydrocladia alternate, 

 laterally compressed, composed of une(iual internode.s, each bearing a 

 group of three to live (usually four) hydrothecte on its anterior aspect. 



HydroihecM' tubular, flattened, curved forward and outward, arranged 

 so as to project alternately to the riglit and left. Aj)erfnie triangular 

 or flattened oval, opening outward and forward, furnished with oper- 

 cula, only slightly gibbous proximally, the sides being nearly parallel, 

 the top of one reaching not more than about one-third the height of 

 the next above. ' 



Gonosome. — Unknown. 



Locality. — Puget Sound. Dredged by the Young Naturalists' Society 

 in the summer of 1895. 



This species seems to me to be fairly distinct from //. falcata, with 

 which 1 have directly compared it, being more slender throughout, with 

 hydrothecte much less crowded, more slender, and having their distal 

 ends more distinctly curved outward and forward. The internodes in 

 H. falcata bear groups composed of a considerably greater number of 



' The genus Haloikema appears to me to be fonnded on insufficient characters, 

 embodying uo really new features, according to the author's description and the 

 type specimen which I have examined. The hydrantlis arc more or less nonre- 

 tractile in many species of the old genus Halecium. The simple stem is found in 

 H. teneUtim Hincks, and the manner of growth strongly reseiuMe.s that of a young 

 specimen of the last-mentioned species, from which, however, it is very well sepa- 

 rated by other characters. 



2 Notes on the Hydroids of Plymouth, .lourn. Marine Biol. Assoc, I, pp. 395-398. 



