EEPOET ON THE HYDROIDA, 21 



Zamboanga — whicli in the form of the hydrothecee and in the general habit of the colony 

 closely approaches Plumularia dolichotheca. It differs from it, however, in every internode 

 of the hydi'othecal pinnge carrying only one hydrotheca, and in the opposite instead of 

 alternate disj^osition of these pinnae. 



Plumularia dolichotheca was dredged off Zamboanga, Philippines, 3uth January 1875, 

 from a depth of 10 fathoms. 



Plumularia insignis, n. sp. (PI. II.). 



Trophosome. — Colony attaining a height of about eighteen inches, main stem fascicled, 

 sending off in all directions simple jointed branches, along whose entire length the hydro- 

 thecal pinnEe, about two-tenths of an inch in length, are alternately disposed. Hydro- 

 thecae deep conical, adnate by their entire height to the supporting internodes, which are 

 separated from one another by an intervening much shorter internode, destitute of hydro- 

 theca; mesial nematophores situated one on the hydrothecal internode at the proximal side 

 of the hydrotheca, and one on each of the intervening internodes. 



Gonosome.- — Gonangia situated on the hydrocladia-bearing branches, each at the base 

 of a hydrocladium. 



This very beautiful species is rendered especially striking by its large size and its 

 plume-like ramification. The gonangia present in the specimen seem to be young, and to 

 have scarcely yet attained their ultimate form. Several specimens of a little isopodous 

 crustacean continued to adhere to the stem, and are represented in the drawing. 



Station 145, December 27, 1873, lat. 46° 40' S., long. 37° 50' E.; depth, 310 and 

 150 fathoms. 



Plumularia ahietina, n. sp. (PI. III.). 



Trophosome. — Colony attaining a height of about nine inches, main stem fascicled for 

 some distance from its root, and sending off scattered, usually simple jointed branches, 

 which carry alternate hydrothecal pinnse, rather less than two-tenths of an inch in 

 length, and commencing from a point at some distance from the origin of the branch. 

 Hydrothecse deep conical, adnate by their entire height to the supporting internodes, which 

 are separated from one another by an intervening much shorter internode, destitute of 

 hydrotheca; a single mesial nematophore, borne by the hydrothecal internode at the proxi- 

 mal side of the hydrotheca, and another on each of the intervening internodes. 



Gonosome. — Gonangia ovate, borne by the hydrocladia-bearing branches, each close to 

 the origin of a hydrocladium. 



The Hydroid here described comes very near to Plumularia insignis ; indeed, so nearly 

 related are the two forms, that we should almost be justified in regarding the difference 

 between them as merely varietal. 



