THE PLUMULARITXE. 57 



each hydrotheca, one on each intermediate iuternode, one in the axil of each hydrocladium, and 

 one on each iuteruode of the main stem. 



Gonottome. Gonangia (female) greatly elongated, produced above into a long, narrow neck, 

 inserted near the axils of the hydrocladia and about twice as long as the internodes of the stem. 

 Gonangia (male) "linear oblong, slender, smaller than the female, less produced above, and 

 tapering to a flue point with a very minute terminal aperture." 1 



Distribution. Coasts of Europe and Great Britain; 1 Key West, Florida; 2 Santa Barbara, Cal- 

 ifornia, collected by Mrs. Virginia Barrett Gibbs. 



A very distinct variety of this species was secured by the Albntrons from floating gulf weed, 

 which differs from typical specimens in being very minute, rarely attaining more than inch in 

 height, is quite rigid, irregularly branching, and has very slender hydrocladial internodes. 

 Unfortunately, none of the specimens had the gouosome and hence we are obliged to regard this 

 very minute and delicate hydroid as a somewhat aberrant form of P. sfttocea, although 1 strongly 

 suspect that the gonosome would demonstrate its validity as a distinct species. 



The specimens collected at Santa Barbara by Mrs. Gibbs are quite typical, being perhaps a 

 little stouter and larger than specimens from Guernsey. 



PLUMULARIA MEGALOCEPHALA Allman. 



(Plate I, fig. 5.) 

 Pliiinularia megalocepliala AI.LMAN, Mem. Mus. ( 'omp. Zool., 1877, V, Xo. 2, p. 31, pi. xix. 



Trophosomc. Colony attaining a height of about 3 inches, branching in an irregular manner, 

 the branches being rather stout and rigid; stem and branches not fascicled, divided into iuteruodes 

 each of which bears a hydrocladium on a long process from its distal end, the process having an 

 elevation on its upper side; hydrocladia alternate, slender, the first iuternode bearing no hydro- 

 theca and the remainder of the hydrocladium consisting of alternate hydrothecate and intermediate 

 internodes, the former being the longer. This is the general arrangement only, and is frequently 

 departed from, both by the intercalation of extra intermediate iuteruodes and the obliteration of 

 the regular ones. Hydrocladia alternate as a rule, but uot regularly so in some specimens, where 

 they are occasionally opposite toward the distal end of the stem. Hydrotheca distant, small, cup- 

 shaped; supracalycine ueniatophores rather large; one mesial uematophore at the base of each 

 hydrotheca, two on each intermediate internode of the hydrocladium, one or two in the axil of 

 each hydrocladium, and two on each iuternode of the stem; hydranths very large and unable to 

 retract fully within the hydrothecse. 



Distribution. Off Alligator Beef, U fathoms. Albatross Station 2069, lat. N. 31 09', long. W. 

 79 33', 352 fathoms. 



The type specimen at Cambridge shows a great irregularity in the arrangement of the 

 internodes. The species is evidently very near P. Jiliculii, from which it differs chiefly in its 

 manner of growth, irregularity of branching, and the size of the hydranths. 



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



PLUMULARIA OLIGOPYXIS Kirchenpauer. 

 (Plate I, figs. 6,7.) 



Pliimnlaria olif/opi/fis KIRCIIENPAUER, Ueber die Hydroidenfamilie Plumnlarida>, 187f>, Ft. 2. p. 48, pi. vi, fig. 9. 

 Plumularia uligopi/fis MARKTANNER-TuRNKRETSCHER, Die Hydroideii des k. k. uaturhist. Ilofniuseums, p. 254. 



Trophosomc. Colony attaining a height of about 1 inch, uubrauched; stem divided into 

 regular internodes, each of which bears a hydrocladium on a process from its distal end; hydro- 

 cladia alternate, short, those on the proximal portion of the stem consisting of a single hydro- 

 thecate iuternode, and those on the distal portion consisting of a short proximal interuode, then a 

 hydrothecate internode, then a longer intermediate internode followed by a second hydrothecate 



1 Hincks, History of British Hydroid Zoophytes, isii8. p. 297. 



-A specimen of this species from Key West is in the Mnseum of Comparative Zoology at Cambridge and is 

 labeled "Key West, Fla., Agassiz." 



