AMERICAN HYDROIDS. 129 



NUDITHECA DALLI (Clark). 



(Plate XXXIV, figs. 1-6.) 

 Maororliynchia dnllii CLAKK, Proc. Acad. Nat. Sci. Phila., 1X76, p. 230, pi. xi. 



Trophoaome. Colony branched, attaining a height of 5 inches; stein coarse, strongly fascicled; 

 hydrocladia closely approximated, compound; consisting of a main straight branch, which usually 

 gives oft' three branchlets from its proximal portion; main branch hydrothecate, except in the 

 region from which the brauchlets originate; brauchlets regularly hydrothecate, with a hydrotbeca 

 in the axil of each; hydrocladia divided into short internodes, each with a strong internal septal 

 ridge opposite the base of the hydrotbeca and another opposite the supracalycine nematophores; 

 proximal portion of each iutemode very broad, forming a shoulder on its front side, upon which 

 the hydrotheca rests. Hydrotheca' broad, cupshaped; margin slightly expanded and smooth; no 

 iutrathecal ridge; supracalycine nematophores broad, somewhat expanded above, and with a strong 

 internal ridge near the base; mesial nematophores resting on the broadened base of the internode, 

 short and free, slightly expanded above. There are two or three nematophores on each iutemode 

 of that portion of the main branch of the hydrocladiuui which bears branchlets; cauline nemato- 

 phores numerous. 



Gonosome. Gonangia very large, long, almost cylindrical, borne on the branchlets of the 

 hydrocladia on the distal part of the colony. There are two or three uematophores near the base 

 of each gouangium. 



Distribution. Unalaska, Alaska. Found on the beach. (I)all.) Specimens which I suppose 

 to be the original types of this species are in the museum of Yale University. 



STREPTOCAULUS Allman. 

 Strejitocautns AI.I.MAN, Challenger Report, Hydroida, 1883, Pt. 1, p. 48. 



Trophoxome. Hydrocladia disposed in a continuous spiral round the stem. Hydrothec;e with 

 entire margin. Mesial nematophore not adnate to the walls of the hydrotheca. 



Gonosome. Gonangia borne on unbranched, jointed appendages of the hydrocladia, springing 

 from the side of a mesial nematophore. 



This, as Professor Allman remarks, is "rendered very striking by the spiral instead of pinnate 

 disposition of the hydrocladia." It is as if the hydrocladia had grown on one side of the stem 

 only, and then the stem had been twisted so as to throw the unilateral hydrocladia into a spiral. 



STREPTOCAULUS PULCHERRIMUS Allman. 

 (Plate XXXIV, figs. 1-3.) 



Streptocaulns pitlcherrimiis ALLMAN, Challemjer Report, Hydroida, 1883, Pt. 1, p. 48, pi. I. 

 Streptoeauliis pitli-tierrimiis QUELCH, Ann. and Mag. Nat. Hist., 5th BIT., XVI, 1885, p. 11. 



Trophosome. 1 Colony attaining a height of about inches; stem simple, fascicled, wavy; 

 hydrocladia nearly an inch in length, occupying about the distal half of the stem. Hydrothecii' 

 deep, thimble-shaped, margin with a single toothlike extension in front; mesial ueinatophore in the 

 form of a free conical spine, with a terminal and a lateral aperture, springing from a point of the 

 hydrothecal int.ernode immediately below the hydrotheca; lateral nematophores pyriform, over- 

 topping the hydrotheca. 



Gonosome. 1 Gouangia sessile, elougato pyriform, with a suboval, subterminal orifice, borne on 

 appendages of the hydrocladia, which are uiibranched and jointed, each joint being obconical. The 

 appendages spring from immediately below the base of a hydrotheca (apparently not the proximal 

 one) at the side of the mesial nematophore. 



Distribution. Porto Praya, St. Jago, from a depth of 100 fathoms. From the cable, off the 

 Cape Verde Islands; depth, over 500 fathoms. 



Type. In the South Kensington Museum, London. 



'Description quoted is from Allnian, in the Challeni/er Report. 

 - Description condensed from that given by Quelch. 



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