122 AMERICAN HYDROIDS. 



ABIETINARIA COSTATA (Nutting). 



(Plate XXXVI, tifis. 9-12.) 

 Thuiaria coslata NUTTING, Hyilroids of the Harriman Expedition, 1901, ]>. 187. 



TwijiliiixoiiK. Colony attaining a height of about H inches. Main stem straight, the 

 proximal part unbranched and divided into regular internodes, each of which bears a pair of 

 subopposite hvdrotheca. 1 , nodes oblique, the upper part of main stem divided into regular inter- 

 nodes, each of which bears a branch and two hydrotheca? on one side and a single hydrotheca on 

 the other. Branches alternate, dichotomously branching several times so as to form a dense 

 tuft; internodes unequal, each bearing several pairs of subalternate to subopposite hydrotheca'. 

 Ilvdrotheca? resembling' those of A.Jtlicula. and A. incmistcms^ as large as the latter, but not so 

 thick and heavy, leaning forward so that their distal ends are not in the same plane with the 

 branch; distal one-third free, constricted, narrowing to a round aperture, which points upward 

 and often a little inward toward the, stem; perisarc thickened on the inner wall just below the 

 margin, furnishing the base of attachment for the one-flapped operculum. A chitinous thickening 

 projects downward from the inner and lower corner of each hydrotheca. 



(TOIIUXIDIK:. (ronangia very numerous, borne on both faces of the stem, and often on basal 

 parts of branches, oblong-ovate, with a small tubular neck and round aperture, sides marked by 

 about live meridional ridges, the crests of which are colored black, making a conspicuous marking. 



Distribution. Yakutat, Alaska (Nutting). 



Although this species is doubtless allied to ^L inconstant, it differs considerably in detail, 

 being much less woody and heavy, and the branches subdividing to a much greater extent. The 

 gonosome is quite distinct. The only specimens known were collected by the Harriman Alaska 

 Expedition. 



In its trophosome this species is quite similar to ^-1. cod Nutting, but the gonosomes of the 

 two are widely different, the longitudinally ribbed gonangia of the former being of a rare type 

 in this genus. 



Tyjx .v/,V, x. Cat. Nos. 19907. 1990S, U.S.N.M.; Cat. No. 18750, Museum of State Univer- 

 sity of Iowa; also in the collection of the author. 



ABIETINARIA ANNULATA ( Kirchenpauer ). 



(Plate XXXVI, fij;s. l.S-lo.) 

 Thiiliiriaiiiiniiliiln KIHCHENPAI-ER, Nardiwhe ('iattuiigen, 1SS4, ]>. I'll. 



Trophosome. Colony about 4- inches high. Main stem and branches exceedingly thick and 

 woody, black in color; the main branches spring from near base of stem, and the whole colony 

 greatly resembles that of the plumularian .\mlitln-cii dnUi in general appearance and habit of 

 growth. Stem and main branches straight, divided into irregular internodes, each of which bears 

 several closely approximated and upward-directed branches each with an axillary hydrotheca; 

 internodes with wide shallow and equidistant annotations, which in a general way correspond in 

 number to the hydrotheca- on each side of the internode. Branches divided into irregular and 

 distant internodes. each with several hydrotheca^ on each side. 



Ilvdrotheca 1 subopposite, very closely approximated, short, stout, tubular, with slight! v 

 constricted distal ends: margin even, aperture nearly round, and either horizontal or slightly 

 inclined toward the stem. Operculum of one flap attached to adcauline side of margin. 



Gonosome. Not known. 



Distribution. The original description was taken from a specimen without a label indicat- 

 ing locality. The above description is from a specimen in the U. S. National Museum, Albatross 

 Station 3o4i, lat. N. 5-1 !:>', long. W. 1(J;1 -ki'. ?>(> fathoms. 



This species has an exceedingly thick and coarse annulated stem that at once distinguishes it 

 from any other . [/>/> tiiini'iii that I have seen. 



Type. In Leipsic Museum. 



