68 



AMERICAN HVDKOIDS. 



PLUMULARIA PAUCINODA, new species. 

 (Plate VIII, tigs. 7-!L I 



Trophosome. Colony (incomplete) attaining a height of li inches, unbranched; stein fascicled, 

 irregularly divided into internodes; hydrocladia borne on a tube running along the face of the 

 stem and branches, supported on stout projections from the stem, divided into long, irregular 

 internodes, each bearing several (about four) hydrotheca'. Hydrotheeffi rather distant, deep, 

 anterior margin slightly deflected, aperture circular and entire; supracalycine nematophores borne 

 on projections from the hydrocladium near the level of the top of the hydrothec;c; a mesial uema- 

 tophore on a projection just at the base of each hydrotheca, and two others between this and the 

 next hydrotheca below; cauline nematophores distributed along the anterior cauliue tube from 

 which the hydrocladia spring. 



Gonosome. Unknown. 



Distribution. Albatross Station 2330, lat. JST. 23 10' 48", long. W. si' !!' l.V, 1'Jl fathoms. 



This species differs from all the other representatives of the genus in having several hydro- 

 theca' borne on a single internode, a feature found in the genus Diplopteron. In the absence of 

 the gonosome, the place here given the species is of course provisional. 



Type. Alcoholic specimen in United States National Museum. 



ANTENNULARIA Lamarck ( modified). 1 



Xemertesia LAMOUROUX (modified), Hist, des Pol. coral. Hex., 1816, p. 161. 

 Antennularia LAMAKCK, Hist. Nat. des Aniiu. saus Vert., 183fi, II, p. 155. 



Trophiisniite. Cinnosarc of stem caualiculated; hydrocladia usually arranged in verticils, but 

 sometimes scattered irregularly over the stem. Nematophores large, trumpet-shaped. 



Gonosome. Gonangia borne on processes from the stem, usually oblong-ovate, or sac-shaped, 

 and without protective appendages. 



In his Report of the Ilydroida of the Gulf Stream (1877), All man separated from the genus 

 Antennularia a species characterized by having the hydrocladia scattered over the stem instead of 

 being arranged in verticils. For this species he constituted the genus Antennopsis. In his Report 

 on the Plnmularidse secured by the Cluillciifler, Professor Allman abandons the genus Aiifetniopnis 

 as untenable. In the former work, however, he points out a much better generic character, but 

 evidently did not at that time feel justified in adopting it. He says: 



In all the species of Antennularia which I have examined the cimosutc is eanalicnlated, the hydrosomal cav- 

 ity being thero represented by a. network of intercommunicating canals. In .[iitennnpsis liippuris the hydrosomal 

 cavity is of the ordinary simple type, but we do not yet know enough of the species which may compose the genus 

 Jntenaopnis to enable us to regard this as a true generic character. - 



A number of species brought to light since the above was written indicate that the canalicu- 

 lated crenosarc is a good generic character. Its adoption will exclude, however, Antennularia 

 fascicularis, described by Allman among the Challenger Plumularida-. 



Distribution of American species of Antenniilariii. 



' See discussion of genus Plumularia, especially the confusion regarding the generic names introduced by Lamarck 

 and Lamouroux. 



'Memoirs of the Museum of Comparative Zoology, V, No. '2, p. 34. 



