THE PLUMULAKUXE. Ii3 



hydranths very large, not capable of retracting into the hydrotheca.'; tentacles 16 to 18; proboscis 

 greatly expanded in the shape of a broadly flaring trumpet. 



Gonosome. Not known. 



Distribution. Barracuda Hocks. Collected by Alexander Agassiz during the cruise of tbe 

 Wild Duck in the West Indies in 1893. 



A very distinct and delicate species, characterized by a proximal hydrothecal internode, and 

 the apparent absence of the supracalycine ueuiatophores, a feature occurring also in Plumularia 

 pinnata of Lamarck. 



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



PLUMULARIA CAULITHECA Fewkes. 



(Plato V, figs. 3-5.) 

 Plumularia cauHthecn FEWKES, Bull. Mus. Comp. Zool., 1881, VIII, No. 7, p. 130. 



Trophosome.^ Colony unbranched, attaining a height of about 2 inches; stem fascicled, the 

 anterior tube bearing the hydrocladia not divided into distinct internodes. but giving off long and 

 strong processes which bear the hydrocladia; hydrocladia not closely approximated, divided into 

 regular long internodes, each of which is hydrothecate and has its cavity partly divided by 

 numerous strong septal ridges which are irregular in distribution, being in general more pro- 

 nounced in the proximal than in the distal iuteruodes. Hydrothecse distant, deep, entirely aduate 

 to the hydrocladia, aperture horizontal, margin slightly flaring, anterior outline slightly sinuous; 

 nematophores very minute and many of them absent in the type; supracalycine pair arising from 

 minute processes on a level with the top of the hydrotheca, a mesial nematophore on a prominence 

 on the front of each end of each internode; cauline nematophores scattered over the anterior tube 

 of the stem, and a spur-like one near the axil of each hydrocladium. There is an aperture in front 

 of the base of each process of the stem which bears a hydroeladinm. 



Gonosome. Not known. 



Distribution. Blake Station 1264, off Grenada, 416 fathoms; Albatross Station 2667, lat. N. 

 30 53', long. W. 79 43', 273 fathoms. 



P. caulitheca stands almost on the line of demarcation between the uttenuata and macrotheca 

 groups, the hydrocladial internodes all being hydrothecate, and the hydrotheca being almost, 

 sometimes fully, one and a half times as deep as wide. The spur-like nematophore in the, axil of 

 each hydrocladia is a common occurrence among the Eleutheroplea, especially those from the West 

 Indian region. 



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



PLUMULARIA ATTENUATA Allman. 

 (Plate V, fig. 6.) 



Plumularia atteniiata ALLMAN, Mem. Mus. Comp. Zool., 1877, V, No. 2, p. 30, pi. xvm. 

 Plumularia atteniiata FEWKES, Bull. Mus. Comp. Zool., 1881, VIII, No. 7, p. ll'S. 



Trophosome. Colony attaining a height of about 2 inches, growing in tufts of plumose 

 branches which are sometimes fascicled below; branches divided into distinct iuternodes below 

 and indistinct interuodes above, where the joints are sometimes not discernible. Each interuode 

 bears a hydrocladium on a projection from Its distal end; hydrocladia with a short proximal 

 interuode without a hydrotheca, followed by a long internode with a hydrotheca near its enlarged 

 proximal end and having the distal end long and attenuate. This attenuate portion may be 

 broken up into one or more intermediate iuteruodes, but normally each internode bears a hydro- 

 theca. Hydrotheca} rather small, cup-shaped; supracalycine ueuiatophores large; one mesial 

 uematophore on the proximal end and one on the distal end of each iiiternode ; one on the proxi- 

 mal node, a pair at the axil of each hydrocladium, and two to each joint of the stem. . 



Gonosome. Not known. 



Distribution. Off Boca Grande, 105 fathotns; Grenada, 576 fathoms (Blake). 



Type.Iu the Museum of Comparative Zoology, Cambridge, Massachusetts. 



'Description of Doctor Fewkes's type specimen in the Museum of Comparative Zoology. 



