THE PLUMULARIDJE. 99 



in allied species; supracalycine nematophores small, slightly overtopping the hydrotheca; mesial 

 nematophore small, with the distal portion projecting almost at a right angle to the axis of the 

 hydrotheca; cauline nematophores forming spiirs on the front of each internode. 



Gonosome. A single, very short, robust corbula attached below the regular hydrocladia, and 

 composed of four very broad pairs of leaves, each of which bears a row of large nematophores 

 along its distal edge; each leaf is scalloped on its posterior edge, making a series of small perfora- 

 tions between the nematophores. There is a considerable portion of the lower proximal part of 

 each leaf cut away. A single hydrotheca is placed between the gonophore and the stem. 



Locality. Near Little Cat Island, Bahamas, shallow water; State University of Iowa 

 Expedition. 



This is the smallest and most delicate species of the genus. The entire absence of a hydro- 

 thecal keel, together with the very short and stout corbula, will serve as diagnostic characters. 



Type slides. Cat. No. 18655, CT.S.N.M.; Cat. No. 15362, Mus. State Univ. Iowa; also in the 

 collection of the author. 



AGLAOPHENIA PERFORATA Allman. 



(Plate XXI, figs. 14, 15.) 

 Aglaophenia perforata ALLMAN, Journ. Linn. Soc., Zool., XIX, p. 150, pi. xxi. 



TrophosomeJ Stem simple, mouosyphonic, springing at intervals from a creeping stolon 

 * * * (not exceeding one-fourth of an inch in height). Hydrotheca' wide, margin with about 

 five teeth on either side, and a single mesial tooth in front. Intrathecal ridge strong, transverse, 

 situated at the junction of the middle and posterior third of the hydrotheca; mesial nematophore 

 adnate to about the posterior third of the hydrotheca, and then terminating in a short free process 

 which is separated from the adnate portion by an imperfect septum; lateral nematophores scarcely 

 overtopping the hydrotheca. 



Gonosome. Corbula closed, deep and rather short, with about nine pairs of costiB; sutures of 

 costin with a wide aperture between every two denticles; peduncles short, carrying a single 

 hydrotheca. 



Locality. St. Vincent Island. 



The specimen was found creeping over a piece of gulf weed. 



This species is evidently near .1. minima, from which it differs, according to Professor All- 

 man's figure, in being obconical in shape, the top being much wider than the bottom, and in 

 having more leaves to the corbula, the leaves not having their proximal and basal portions 

 largely cut away. It can be told from any others of the minima group by the absence of any 

 hydrothecal keel. Professor Allman does not state whether it has the peculiar uematophores or 

 processes at the bases of the hydrocladia which characterize the rest of the group. 



AGLAOPHENIA SIMPLEX ^d'Orbigny). 

 (Plate XXII, fig. 1.) 



Plumiiluria simplex n'ORBiGNY, Voyage dans 1'Amorique Meridionale, 1839-46, V, p. 27, pi. xm. figs. I, 2. 

 Aglaophenia simples KiRCHENi-ArEU, I'eber die Hydroidenfamilie Plumularida', 1872, Pt. 1, pi. I, fig. 1. 



Never having seen this species, nor an adequate description, I copy the original description 

 verbatim : 



P. surcitUs simplicibug, alternatis pinnatii; rellidis timpUcibus; apertiira denticulata. 



Cette espece, fixe snr des Sari/annum, presents seulement de petites branches pennies simples, qui partent de 

 la rarine rampante. Chaqiie branche se forme de petits rameaux alternes courts; ces rameaux sont seulement 

 art.icules, de distance en distance, par un (Hranglemeut. Chaqne segment a sa cellule portee sur une expansion 

 angulensc, saillante en points. La cellule est simple, globuleuse, entourde de six dents anguleuses, dont deux se 

 trouvent de cbaque cute. 



The figure of this species which I copy does not agree very closely with either the original 

 description nor the figure given by d'Orbigny. Kirchenpauer's figure, however, seems to be based 

 on authentic specimens, and is a much more detailed representation of the species. 



# 



1 Original description quoted from Allman. 



