THE PLUMULARIL^E. 97 



reaching to tbe top of the hydrotheca ; mesial Dematophore rather small, the distal free portion 

 beiug partly separated from tlie remainder by a constriction or partial septum. 



Gonosome. Corbula usually borne on a modified hydrocladium at the base of the expanded 

 or pinnate portion of the colony; corbula short, stout, rounded, composed of eight pairs of 

 rather broad leaves, which meet only at the points where the nematophores project, heuce 

 leaving a row of perforations between adjacent leaves. Bach leaf has a row of large nemato- 

 phores along its distal edge, and a short spiny process at its base. There is usually but one 

 corbula to a colony, and that is proportionately very large. 



I>ixiribntion.La,t. 3'2 43' 25" K, long. 77 20' 30" W., surface?, Fewkes; Gulf of Mexico, 

 Allman; Albatross Station 2038, lat. N. :i.S 31', long. W. 69 08', surface; Albatross Station 2585, 

 lat. N. 39 09', long. W. 72 17', surface, floating in the Gulf Stream and in shallow water ou the 

 Great Bahama Banks. 



This species may be A. pelarjica Lamouroux, being the most common of the minute species 

 found on floating seaweed, but the original description of that species is not sufficiently defi- 

 nite to permit of any certainty of identification. This is the most abundant Aylaophenia in the 

 mimtta group. Having seen the type specimens at the Museum of Comparative Zoology, I am 

 enabled to give a somewhat more extended description than the original. The gonosome has 

 not hitherto been described. Although the present species does not agree in all respects with 

 the description of Alluiau's A. late-carinata, the general agreement is such that I regard the 

 latter name as a synonym. The diagnostic marks of A. iniinita are the broad anterior keel to 

 the hydrotheca in connection with the projections at the bases of the hydrocladia and the 

 regularly annulated rootstalk. 



Doctor Fewkes says that the specimens secured by the lilake were growing on alga. If this 

 is true it is unlikely that they came from the bottom at the depth mentioned, as there is no 

 record that I can find of alga* growing at such depths. 



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



AGLAOPHENIA PELAGICA Lamouroux. 



Aglaophenia pelagica LAMOUROUX, Polyp. Flex., 1816, p. 170. 



1'lumularia pelagica LAMARCK, An. sans Vert.., 1836, 2<1 ed., II, p. 167. 



Di/nanuna pelasgica (DE BLAINVILLE), Manuel d'Aetinologie, 1836, p. 484. 



Aijlaopheuiti pelitsgii-aMcCRAi>\, Gymu. of Charleston Harbor, 1857, p. 98. 



Aglaophenia pclasgica AOASSI/, N. A. Acalopha', 1865, p. 139. 



Aglaoplienia pelagica KIUCHENPAUER, Veber die Hydroidenfamilic Pliimularid;e, 1872, Pt. 1, p. 29. 



The following description is given by McOrady. 1 The words in brackets are my own, and are 

 introduced to make the description more intelligible to those who are used to the present 

 terminology of the science: 



These specimens are attached to the gulf weed [Sargassiim bacciferiim] and were taken in the Atlantic by a 

 homeward bound vessel. It [the species] is characterized by cells [hydrotheca'] unite long in proportion 



to their breadth. The posterior process [mesial nematophore] is far behind; the anterior lateral processes 

 [supraealycine nematophores] are rather weak and slender. The main stem is recumbent and creeping, giving oil' 

 at intervals plume-like branches, so much like those of the ordinary true plumiilaria that it would readily be 

 mistaken at first sight. On my specimens I have found no reproductive capsules [gonangia]. This important 

 portion of the community, however, is represented in Dana's woodcut. It is turned downward, thus 



depending from the stem. Is this its natural position? 



This species is not improbably an occasional visitant of our waters, but I have never encountered it on the Gulf 

 weed thrown on our beaches. 



Distribution. Southern coast of England and Ireland, Irish Channel, Sargossa Sea, and Charleston Harbor. 



As before intimated, it is by no means improbable that this species is identical with A. 

 minuta Fewkes. A good deal of doubt is thrown upon this probability, however, by the fact that 

 no hydrothecal keel is mentioned by McCrady, who was a most careful observer and would 

 hardly miss so conspicuous a character had it been before him. 



1 Gynmophthalrnata of Charleston Harbor, p. 201. 

 12833 7 



