102 AMERICAN HYDR01DS. 



Alaska (Clark); Aleutian Islands (Clark); St. Pauls Island (Clark); Puget Sound (Nutting); 

 Port Townsend (Calkins); San Diego Harbor (Torrey); Greenland (Winther); Polar Sea 

 (Bergh); Iceland (Hincks); Spitzbergen and North Cape (Bonm-vie); British Islands (Hincks); 

 Gulf of Gascony (Bedot); A/f><rfi;>*x Station 2557, lat. N. 39 53' 10", long. W. 71 31', 154 

 fathoms; Station 2850, lat. N. f>4 52', long. AY. 15i 46', 21 fathoms; Station 2857, lat. N. 58 05', 

 long. W. 150 46', 51 fathoms; Station 285S, lat, N. 58 17, long. W. 148 36', 230 fathoms; 

 Station 2865, lat. N. 48 12', long. W. 122 : 4t', 40 fathoms; Station 2860, lat. N. 48 09', long. 

 AY. 125 03', 171 fathoms; Station 3225, lat. N. 54 48' 30", long. W. 165 49', 85 fathoms. 



The bathymetric distribution of this species is phenomenal, being from shallow water to 1,375 

 fathoms. 



S. tricuspidata, like all other wide ranging species, varies greatly, especially in the size of 

 the hydrotheca?. Clarke found specimens in the material collected by Dr. Dall in Alaska that 

 were very much larger than the typical form. (See Plate XXV, fig. 6.) 



S. hesperia- Torrey appears to be a synonym for this well-known species. His figures are 

 exact!}' matched by specimens of S. tr!cuxpi(l<tt in my possession. The size also agrees, and I 

 am unable to find anything in his description by which I can differentiate his species. 



Type- I' 1 Museum of Nat. Hist. Society, Newcastle-upon-Tyne, England. 



SERTULARELLA TROPICA Hartlaub. 

 (Plate XXVI, figs. 3-4. ) 



rariabHii CLARKE, Bull. Mus. Comp. Zool., XXV, 1894, p. 75. 

 d tropirn HARTLAUB, Revision cler Sertularella-Arten, 1900, p. 41. 



Trophosome. Stem sometimes simple, sometimes compound, slightly flexuous, main 

 branches few and irregularly disposed; a pinnate arrangement of the small branches is in some 

 cases well marked. Color, light horn. The hydrothecaj are alternately arranged, usually one to 

 an internode; they are largest near the base, have a tricuspid margin, which is generally 

 thickened and provided with a three-lobed valve; they are strongly divergent and veiy much 

 exserted. The degree to which the}' are embedded in the stem varies greatly; in some cases they 

 are scarcely more than attached to the side of the stem, and in others are embedded more than a 

 third of their length. 



Gonosome. The gonangia spring from just below the hydrothecse, are much elongated, 

 length two and a half to three times their width, the upper portion marked with five or six rings, 

 the opening terminal and tubular, the pedicel extremely short. 



Ditstiilutwn.Alliitroxs Station 3357, lat. N. 6 : 35', long. W. 81 44', 782 fathoms; Station 

 3384, lat. N. 7 31' 30", long. W. 79 14', 450 fathoms; Station 3388, lat. N. 7 06', long. W. 

 79 48', 1,168 fathoms. 



I have not seen this species, and have copied the above description entire from the original 

 by Dr. Clarke, The name given by Dr. Clarke was preoccupied by Bale in 1888 l and by Clarke 

 himself in 1876 ~ and Hartlaub gave the species the name S. tropica. 



The depth from which this species was dredged is quite exceptional for the genus, and 

 indeed for the family Sertularidse. 



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



SERTULARELLA CLARKII Mereschkowsky. 



(Plate XXVI, fig. 5.) 



Ki-i-liiliirillii cliii'kl! MERESCHKOWSKY, Ann. and Mag., 5th ser., II, 1878, p. 447. 

 M-rtiiltiri'Hd darkii HARTLAL'B, Revision der Sertularella-Arten, 1900, p. 25. 



' ' Trophotsoine. Hydrorhiza forming a compact layer of hydrophytons. Hydrocaulus straight, 

 long, cylindrical, not angularly bent, with regular internodes, destitute of branches to the apex, 

 where the width of the axial tube suddenly diminishes considerably, and it at the same time gives 



'Proceedings of the Linna'an Society of New South Wales (2), III, p. 764. 



- Proceedings of the Academy of Natural Sciences of Philadelphia, 1876, p. 1876. 



