130 AMERICAN HYDROID8. 



borne on processes from the primary branches, not divided into internodes. Hydrothecaa in 

 four equidistant rows, tulml:ir, larger liclow. almost completely immersed, margin oval, 

 compressed into angles at the sides, the bottom of one hydrothcca usually being below the level 

 of the top of the one below it. Operculum of a single abcaulinc Hap. 



Cronosomt . Not known. 



r)!xfi-i1>iit!iin. The, only specimen known was found in the I'nited States National Museum 

 collection, labeled lat. N. 60 22', long. W. It is 45', Lieut. George N. Stoney, U. S. Navy. 



This species almost exactly agrees with .S'. y^v>Vi/ Mereschkowsky in the shape and 

 disposition of the hydrothecte, but differs strikingly in the mode of branching, 1 icing the only 

 S,III,/!HI>JIX!K that I have seen with true compound branching in which the stem, primary branches 

 and secondary branches bear the relations to each other that we find in the shaft barb and 

 barbules of a feather. 



TI/J .V//V/.V. Cat. No. I'.islti, U. S. N. iM. Cat. No. ls74(i, Museum of the State University 

 of Iowa; also in the collection of the author. 



SELAGINOPSIS CEDRINA (Linnaeus). 



Merlulariti. rfilriiiii LI.XNMCI s, Systi'iiia Xatur.-i', 175S, p. S14. 



i i-i'iii-iiiii IIoi TIVYN, Xatunrlyke Hist., XVII, 17lil-7:i, p. ">77. 



ri'ilriii'i PALI, AS, Klcnrhus /iiphytorum, 170ti, p. !.'!!>. 

 Hi-rliil<iriii i-i'i/riiin LIXN.KIS Systcuia Xatur.-r, 17t>7, p. 1313. 

 Sertularia cedrina ]'>I>I>I>AEUT, Lyst dcr l'lant-1 lirivn, 17HX, p. 17o. 



S,'rliilnri<i ri'iti-iiiii \\'n. KI\S ami HKKHST, Charakti-nHtik del- Tliirrpllan/.rn, 17S7, p. 177. 

 ,s',r/H//-ir( i;-ili-iii<i (J.MEi.iN, Systema Natura?, (Linnaeus), 17SS-!t:;, p. :;s."i7. 

 SerMaria cedrina I'.usc, Hist. Xat. ilcs \\-rx, III, 1802, IJ, p. tun. 

 .\'ii/i//sl,-inii I X i-li/lin-iii ) ci'ili-iiin OKKX, Lfhrlmrh ilrr Xatui-fri'srliirlilr, Is 15, p. ill!. 

 i'ili-iiiii LAMOUROUX, Hist, des Polypiers, 1816, p. 1!H>. 

 jHirijim MERESCIIKOWSKV, Ann. and Ma^., otlt SIT., II, 1S7S, p. 4:)s. 



Xi'/ili/iiio/ixiK i-i'ili-iilil KlRCHEXPAUEK, Nordiscllr ( ial tnil'.'CIl, 1SSI, p. S. 



"Troplioxoiin'- Hydrocaulus slightly curved, divided into regular intcrnodes. liranches 

 arranged alternately on two sides of the principal stem, two pairs on each internode, divided into 

 five internodes, constricted at the point of attachment and at the internodes. Each branch bears 

 one or two, rarely five, secondary branches. Hydrotheciv cylindrical, almost entirely immersed 

 in the substance of the axial tube; aperture oval, with two angles (not teeth); hydrothecse 

 arranged in four regular series, and at the same time in a spiral, the hydrothecse of each series 

 following one another immediately without leaving any free space or interval. 



" GUIXIXOIIII . Gonangia arranged in two or three series, of an oval form, narrowing gradu- 

 ally toward the base, and truncate at the apex. The surface is ribbed." 



Distribution. Kamchatka (Linna-us); Metschigman Bay (Mereschkowsky); India Point, 

 Bering Sea (Kirehenpauer). 



I have not seen this species, and have copied the most complete description that I could find, 

 that of Mereschkowsky. Kirehenpauer 1 presents such strong evidence that the 8. jmc/p'/'/i of 

 Mereschkowsky is identical with s, rtnl<ti'iii ml rum Linmcns that I have here conformed to his 

 view. 



SELAGINOPSIS PINNATA Mereschkowsky. 



(Plate XXXIX, tig. 6.) 



Selaginopsig pinnata MERESCHKOWSKY, Ann. ami Mai:., ">tli ser., II, 1S7S, p. 4:;ii. 

 Selaginopsis pinnata KIRCIIENPAUER, Nordische Gattungen, 18S4, p. 14. 



Tri>j>/n>tuiiii<: Colony plumiform, attaining a height of about ti inches. Stem not fascicled, 

 but very heavy and woody, divided into internodes which are fairly uniform in length on prox- 

 imal portion and less so on distal portion: nodes very deeply cut. each accompanied by two or 

 more regular annotations; stem bearing two opposite rows of hydrotliee.-e and two opposite rows 

 of branches. Branches borne on very short processes of the stem, and very deeply constricted at 



'Xordische Gattunpi-n iiml Arten, 1SS4, pp. 8 and 9. 



