148 NATUEAL HISTORY OF ARCTIC AMERICA. 



on some of the other tubercles. The form of the body is more or less 

 cylindrical, often t^vo inches or more high aud one in diameter, after 

 ])rescrvation in alcohol. The tubes are terminal and divergent. Color^ 

 in life, reddish. 



The very young specimens are low and nearly flat in contraction, and 

 nearly smooth. 



It is common on the Grand Banks, where it grows to a large size. It 

 has not been found on the New England coast. 



Lot No. 592, head of Cumberland (iulf, attached to roots of kelp,, 

 May 19, 1878. Both adult and young. 



Halocynthia echinata Verrill. 



Ascidia echinata LiXNE. — Fabkicius, Fauua GriJulandica, p. 331. 

 Cynthia echinata Stimp., Invert, of Grand Mauan, p. 20, 1854. — Binney, in Gould, 

 Invert, of Mass. , p. 18, pi. xxiii,fig. 3260. — Verrill, Amer. Jourii. Sci. i,p. 96, 

 1871. 

 V Lot No. 59C, Cumberland Gulf, May 10, 1878. 



Besides the two species of this genus brought home by the expedi- 

 tion, the following occur on the American coast north of Cape Cod: 

 U. injriformis (Eathke), Southern New England to Greenland; H. ml- 

 losa (Fabr.), perhaps young of the preceding, Labrador to Greenland j 

 H. tuherculum (Fabr.) = Cynthia carnea (Ag.) VerriU = G. placenta Pack- 

 ard (young). Cape Cod to Greenland; H. jmlcliella YerriU (as Cynthia), 

 Eastport, Me., to Grand Banks; H. partita (Stimp.), Massachusetts 

 Bay to North Carolina. 



POLYZOA. 



Crisia eburnea (L.) Lamoiirous. 

 Gulf of Cumberland. One specimen. 



Diastopora patina (Lam.) Smitt. 



Annanactook Harbor, on Laminaria, 7 fathoms, May 19; and on 

 Halocynthia rustica, head of Cumberland Gulf, May 5, 1878. 



Alcyonidium mytili Dalyell. 



Gulf of Cumberland, on algse. Godthaab, Greenland, on carapax of 

 Hyas araneus. 



Gemellaria loricata (Linn6) Busk; Smitt. 



GcmcUana dumosa Stimpsox, Invert, of Grand Manan. 

 Specimens three inches high, Penny Harbor, Cumberland Gulf, low- 

 water, October 4, 1877, lots 226 and 238, covered with fry of Crenella 

 faha ; same locality. May 28, 1878. 



