74. THESEA. 47 



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

 striated longitudinally. Axis calcareous. 



Herophylla, Stcenstrup, Over. K. D. V. S. 18G0, p. 121. _ 



Riisea, 'Duchass. ^- 3IicheL Corall. Antilles, p. 18 ; Kolliker, Ic. Hist. 



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

 Riiseas, Snrs. 

 This genus is allied to Fanicidina in the structure and disposition 

 of the polypes when Faniculimi begins to detach its branches. 

 Arranged with Frimnoacece 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, Steenstrup, Overs. K. D. V. S. 1860, p. 121. 

 Hab. Barbadoes (Eiise) ; 2 feet high and ^ foot in expanse with 

 the root. 



B. Polype-cells short, broad, in aUemating series on the txoo sides of the 

 branches. 



73. SWIFTIA. 



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

 Cells prominent, like mammce, 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. 8^ Michel. Corall. Antilles, Svppl. p. 107. 

 150. Swiftia exserta. 

 Coral on a plane ; branches and branchlets subdichotomous ; cells 

 prominent, alternate. 



Gorgonia exserta, Solander 8f Ellis, Zooph. t. 15. f. 1 ; Lamx. {not 



Thesea exserta, Duchass.). 

 Swiftia exserta, ZiwcA-t^ilfjc/i. Corall. Antilles, Su-ppl. p. 107, t. 2. f. 4,5. 



Hah. Island of St. Croix. 



74. THESEA. 



Coral branched ; branches slender. Bark fonned 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. 8f Michel. Corall. Antilles, p. 18 ; Kolliker, Ic. Hist. 

 p. 137, t. 17. f. 18 {not G. exserta, Solander 8f 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 Acis, 

 Duchassaing. 



Intermediate between Muricea and Primnoa. 



