■ . ' ' Alcyo7iaria G 35 



illustrated by him with abundant anatomical and histological observations, 

 though he doubtless erred in making too many species, and 1 -y giving too much 

 importance to variations in the forms of branching. 



When well-grown the polypidom has a stout stalk and numerous branches 

 and branchlets, which bear a multitude of small crowded polyps at their tips, 

 usually three to five in a cluster, with a little or no intervening coenenchyma. 



The branching is usually arborescent and often symmetrical, but variable. 

 The stalk is usually smooth and naked for some distance, and the proximal 

 part of the branches is usually naked. The terminal branches are often clustered 

 into umbel-like groups, and in other cases into cyme-like or thyrsoid groups, 

 usually of three to seven branchlets. 



The polyps are not wholly retractile, and are often partly expanded in 

 alcoholic specimens. The anthocodia is usually pretty well-developed and 

 contains eight double rows of slender spindles and subclavates in chevrons, 

 but the basal wreath of transverse spicules is nearly or quite lacking, so that 

 its limits proximally are not well-defined. The polyps are often uneciually 

 developed in the inner and outer sides, and spicules may be few or none on the 

 smaller inner side; in such cases the polyps curve inward in contraction. 



The spicules of the anthocodia and the tentacles are mostly slender warterl 

 spindles and imperfect clubs. Those of the cortex of the branches and stalk 

 are mostly small warted spindles, sub-clavate forms, double-heads, with more 

 or less compound crosses, double stars, and various small irregular forms. Some- 

 times the lower part of the stalk is nearly destitute of spicules;- the upper part 

 and branches are often without spicules or with few. One of the most salient 

 characteristics is the absence of any well developed wreath of transverse spicules 

 defining the proximal zone of the anthocodia. The rows of spicules run con- 

 tinuouslj', or nearly so, from the anthocodia to the base of the polyp-body with 

 little change, though sometimes the spicules are small, few, or lacking proximally. 

 The tentacles are spiculose usually nearly to the tips, and sometimes in the 

 pinnules also. This genus is in many respects intermediate between Gersemia 

 and Drifa. From the former it differs in having less ccenenchyma, or none at 

 all, between the polyps, and especially in not having a well-developed wreath 

 of spicules defining the anthococha. The spicules are mostly smaller and 

 simpler, and those of the cortex are fewer and more generally small spindles 

 and clubs. Also the polyps are not retractile. From Drifa it differs especially 

 in not having the anthocochal area covered with lacerately lobed or spinose 

 clubs. The latter also has larger and more clavate spicules in the cortex of 

 the branches. It agrees in lacking an anthocodial wreath of transverse spicules. 

 The cymiform or subumbellate mode of branching is also generally distinctive 

 for well-grown specimens of this genus. 



Duva multiflora \'errill. Sea-Cauliflower. 



Alcijonium miiUiflorutn \EB.mi.i.,Fro€. v. S. Nat. Mus., Vol. 11, p. 200, 1879; 

 Ann. Rep. U.S. Fish Comm. for 1883, p. 533, 1885. 



Duva arhorescens Daxielssen, op. cit., pp. 37-41, pi. ii, figs. 42-54: pi. iii, figs. 

 1-17, 1887; prolia))ly also including D. f^pitKhcrdensis Dan., op. cit., pi. iii, 

 figs. 18-29, and D. rosea Koren and Dan., o]). cit., 1883, pi. i. 



Eunephthija rosea IMolander, op. cit., 1915, p. 74, pi. li, figs. 10, 20, 21. 



Plate n'; Fig. 7. Plate XIY; Fig. 6. Text Figs. G, 7. 



Thi 



high, .„.....„„.„,. „.- 



naked; branches very numerous, subuml:)ellate, bearing clusters of small crowded 

 polyps at their tips, and thus in conti'action resembling a cauliflower, giving 

 reason for the name "sea-cauhflower" used liy fishermen. 



This, when well-grown, is a large arborescent s])ecics often 100 to 150 mm. 

 and 75 mm. broad. The stalk is large and smooth; liasal part of Ijranches 



9343— 3i 



