74. THESEA. 47 



shaped, with eight thick ribs ; aperture closed with eight valves, 

 striated longitudinally. Axis calcareous. 



Herophylla, Steenstrup, Over. K. D. V. S. 1860, p. 121. 



Riisea, Duchass, 8f Michel. Corall Antilles, p. 18 ; Kolliker, Ic. Hist. 



p. 140, t. 18. f. 1 (Rusea, by misprint). 

 Riiseee, Sars. 



This genus is allied to FunicvMna in the structure and disposition 

 of the polypes when Funiculina begins to detach its branches. 

 Arranged with Primnoacece by Dr. Kolliker. 



149. Riisea paniculata. 



Coral slender ; bark orange, with a groove on each side of the 

 principal branches ; axis striated, yellow. 



Riisea paniculata, Kolliker, Ic. Hist. 1. 15. f. 7, 1. 18. f. 1, 2 ; Duchass. $ 



Michel. Corall Antilles, p. 18, t. 2. f. 1, 2, 3. 

 Herophylla regia, Steenstrtip, Overs. K. D. V. S. 1860, p. 121. 

 Hob. Barbadoes (Riise) ; 2 feet high and foot in expanse with 

 the root. 



B. Polype-cells short, broad, in alternating series on the two sides of the 

 branches. 



73. SWIFTIA. 



Coral branched. Bark thin, squamulose, without any spicules. 

 Cells prominent, like mammae, squamose, striated, mouths terminal, 

 in alternate series, one on each side of the branches. Polypes 

 cylindrical, hardened, with large decussated spicules externally. 



Axis ? 



Swiftia, Duchass. 8f Michel. Corall. Antilles, Suppl. p. 107. 

 150. Swiftia exserta. 



Coral on a plane ; branches and branchlets subdichotomous ; cells 

 prominent, alternate. 



Gorgonia exserta, Solander fy Ellis, Zooph. t. 15. f. 1 ; Lamx. (not 



Thesea exserta, Duchass.}. 

 S wiftia exserta, Duch.fyMich. Corall. Antilles, Suppl. p. 107, t. 2. f. 4,5. 



Hob. Island of St. Croix. 



74. THESEA. 



Coral branched ; branches slender. Bark formed of small scales 

 and superficial spicules. Cells pustuliform, subalternate on the 

 branches ; outer surface formed of scales, and aperture terminal and 

 radiate. Axis corneous (insoluble in muriatic acid). 



Thesea, Duchass. fy Michel. Corall. Antilles, p. 18 ; Kolliker, Ic. Hist. 

 p. 137, t. 17. f. 18 (not G. exserta, Solander $ Ellis). 



Bark externally squamulose, internally with numerous spicules; 

 cells externally scaly, subalternate, prominent ; mouth radiated. 



When the outer scales have fallen off, the bark is like Ads, 

 Duchassaing. 



Intermediate between Muricca and Primnoa. 



