104 G| Canadian Arctic Expedition, 1913-1918 



Urticina (emended, type assigned) VEKRILL, Trans. Conn. Acad. Science, vol. 

 I, p. 469, 1869; Comm. Essex Inst., Vol. VI, p. 62 (28), 1869. 



Actinians, often of large size, with numerous large retractile tentacles, 

 usually perforate at tip. Column furnished with longitudinal rows of small 

 retractile suckers capable of attaching foreign objects, but usually small and 

 inconspicuous when contracted or not in use, or they may appear nearly obsolete. 

 A feeble parapet. 



Sphincter muscle very large, endodermal, circumscribed or cordiform. 

 Perfect and imperfect mesenteries numerous; nearly all of the perfect ones, 

 except the directives, may bear gonads, as well as many of those that are imper- 

 fect; those of the first and second cycles often sterile. The type species may be 

 hexamerous, octamerous, or decamerous, most frequently decamerous. Neither 

 acontia nor cinclidse. Circular muscles of the tentacles may be partly ecto- 

 dermal and extend into the mesoglcea or they may be entirely mesoglceal. 

 Type species is viviparous. 



Urticina crassicornis, (Mull.) Ehr. 



Actinia spectabilis ? O. FABEICIUS, Fauna Gronlandica, p. 351, 1780. 

 Rhodactinia davisii'Ao., op. cit., 1847. VERKILL, Mem. Boston, Soc. X. Hist., 



Vol. I, p. 18, pi. 1, fig. 9 (descriptions, variations in colours, etc.), 1864; 



Amer. Naturalist, Vol. II, p. 259 (habits). 

 Tealia crassicornis (MiiLLER, 1776). GOSSE, Actinologia Brit., p. 209, pi. IV, 



fig. 1, (coloured). ANDRES, op. cit., p. 199, fig. 24, 1884. PARKER, Amer. 



Nat., XXXIV, p. 752, fig. 9, 1900. HARGITT, Anthozoa Woods Hole 



Region, p. 244, figs. 3, 4 (sections), 1914. 

 Urticina crassicornis E!IRENBERG, 1834, p. 33. VERRILL, Trans. Conn. 



Acad. Science, Vol. I, p. 469, 1869; Comm. Essex Inst., Vol. VI, p. 62, 



1867; Howgate Polar Exped., p. 152; also of many later articles; Amer. 



Journ. Science, Vol. VII, p. 216, 217, fig. 32 (hexamerous), 1899. 

 Rhodactinia crassicornis (pars) CARLGREN, Olga Exped., Actin., p. 39, 1909. 



CLUBB, (pars) Nat. Antarctic Exped., vol. IV, p. 9, pi. iii, fig. 22 (photo- 

 graph of English specimen), 1902. 

 Urticina felina McMuRRicn, Trans. Royal Soc. of Canada, vol. IV, section 4, 



pi. 1 (general fig. coloured); pi. ii, figs. 2-4, (sections); pi. iii, fig. 5, (section), 



1910, (not A. felina of Linnaeus). 



Plate XIX; Fig. 4. Plate XX; Fig. 13. Both from life. Plate XXVI; 

 Fig. 7. Plate XXXI; Fig. 5. 



This when well grown is a very large, stout, and bright coloured species, 

 with a great number of large, thick tentacles, usually banded with red and 

 white. In large specimens there may be 150 or more. 



The exterior of the column usually has many longitudinal rows of rather 

 distant, very small, imperforate suckers, which are capable of attaching foreign 

 objects, though more frequently, when in still or deep waters, none are carried. 

 These suckers are seldom conspicuous and when not in use are often so retracted 

 as to be hardly noticeable, especially in specimens from rather deep water, thus 

 contrasting with the species of Tealiopsis, in which they are conspicuous and 

 persistent. The column wall is very soft, flexible, and changeable in form. 



The tentacles can be entirely retracted and the capitulum and column 

 margin rolled inward over the disk. The form, therefore, is very variable in 

 specimens more or less contracted. In full expansion the height usually exceeds 

 the diameter of the body, which may be cylindric, or swollen in the middle, or 

 distally, etc* 



