THE PLUMULARIPJE. 75 



The very dark color of the fascicled main stem and branches, together with the regular and 

 emphatic geniculations of the latter, make this a very well-marked form. 



Type sliiles.C.at. Nos. 18567, 18568, U.S.N.M.; Cat. No. 11685, Mus. State Univ. Iowa; also in 

 the collection of the author. 



ANTENNOPSIS ANNULATA (Allman). 

 (Plate XII, figs. 7-9.) 



HippiireUa annulala ALI.MAN, Mem. Mns. Comp. Zool., 1877, V, No. 2, p. 36, pi. XXI. 

 Aiiteniiopsis ramosa FEWKES, Bull. Mus. Comp. Zool., 1881, VIII, No. 7, p. 133, pi. HI. 



Trophosome. Colony attaining a height of 6 inches, pinnately branched basally and irregu- 

 larly branched distally; stem fascicled, branches not fascicled, divided into interuodes, each of 

 which bears a hydrocladiiim on a long process from its distal end; hydrocladia alternate on 

 proximal portion of branch, scattered or verticillato on distal portion, and divided into alternating 

 long hydrothecate and short intermediate internodes, there being usually three closely approxi- 

 mated annnlatious at the nodes. Hydrothec;v deep, cylindrical, with entire slightly everted 

 margins; supracalycine nematophores borne on processes from the internode; one mesial nemato- 

 phore at the base of each hydrotlieca and another on the proximal end of the intermediate 

 iuternode; a cauliue uematophore on each hydrocladial process of the branch and one on the 

 proximal part of each internode. 



Gonosvwe. 1 Gonangia long, with a somewhat bottle-shaped neck, approaching those of 

 Plumularia xetacea in shape, and found singly in the axils of the hydrocladia. 



Distribution. Off Pacific Eeef, 283 fathoms (Pourtales); Blake, off Savannah, 229 fathoms; 

 Albatross Station 2601, lat. N. 34 39', loug. W. 7".o 33', 107 fathoms. 



A specimen distinctly referable to this species is among the Albatross material from the 

 West Indies. The gonosome was fortunately present and proved to be quite characteristic of the 

 genus Antennopxiii. The genus Hippurella, as established by Allman on the arrangement of the 

 hydrocladia, I do not regard as tenable on account of the complete intergradatiou between 

 Hippurella and Antennopxis. 



The type ofAntrnnopsin rnmosa which Doctor Faxon sent me from the Museum of Comparative 

 Zoology, bearing the locality label quoted in the description, I am unable to separate from 

 Hippurella annulata of Allman. The trophosome agrees in every detail with Allmau's description 

 and figures of the latter species and with Albatross specimens that must be referred to this 

 species. 



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



MONOST^ECHAS Allman. 

 MonnstnvliaK ALLMAN, Mem. Mus. Comp. Zool., 1877, V, No. 2, p. 36. 



Trophosome. Colony branched, usually in a dichotomous manner; stem not fascicled; hydro- 

 cladia always springing from the upper sides of the branches; otherwise closely resembling those 

 of Plumularia, especially the catliarina group, from which it differs in the entire absence of 

 cauliue hydrotheca-. 



Gonosome. Gonangia without protective branches of any kind, ovate, with terminal or 

 subterminal apertures. 



MONOST/ECHAS QUADRIDENS i McCrady). 

 (Plate XIII, figs. 1-4.) 



Plumularia i/iiaiJriilfiiH MrdiAi'Y, Pnio. Elliott SOP,., April, 1857, p. 97. 

 Plumularia nitadridens Louis AGASSIZ, Cont. Nat. Hist. U. S., 18(52, IV, p. li.'iS. 

 riiiiiniJaria quadi-idi-nx Ai.KXANHER AGASSIZ, North Amer. Acalephm, 18li."i. p. 110. 

 Mononlu-ettas dieholoma ALLMAN, Meiu. Mus. Comp. Zool., 1877, V, No. 2, p. :!7. 



diflinlomii KK\\ KKS, Hull. Mus. Comp. Zool., 1881, VIII, No. 7, p. 128. 



Trophosome. Colony attaining a height ot 6 inches, tlabe.llate in general form, branching 

 dichotomously ; stem not fascicled, with indistinct interuodes and branching at irregular intervals, 



1 Hitherto uudescribed. 



