INTRODUCTION. lxxxi 



8. Genus Solanderia. 



Duchassaing and Michelin, in Guerin's Revue Zoologique, June, 1846. 



Differs from Gorgonia by the suberous texture of the sclerobasal axis, which resembles 

 the non-calcified joints of Melitaea. 



Typ. sp., Solanderia gracilis, Duchassaing and Michelin, loc. cit. 



9. Genus Briarettm. 



Blainville, Manuel d'Actinologie, p. 520, 1830. 



Axis soft, suberous, or composed of spicula. This genus is intermediate between 

 Alcyonium and Gorgonia. 



Typ. sp., Briareum gorgonoideum, Blainv. ; Gorgonia briareus, Lin. ; Ellis and Solander, tab. xiv, figs. 1, 2. 



The genus Hyalonema established by M. Gray, (' Proceed, of the Zool. Soc' 1835, 

 p. 6H,) is also referred by some zoologists to the tribe of Gorgoninae; but the recent 

 observations of M. Valenciennes tend to establish that the fasciculi of siliceous threads, 

 which constitute the axis of this singular production, belong to the class of Spongidse, and 

 the polypi which we have observed in a dried state on different parts of the axis appeal* to 

 be parasites, belonging to the order of Zoantharia. 



Second Tribe— ISINjE. 

 Dana, Exploring Exped., Zooph., p. 677, 1846. 



Common axis articulated, or composed of segments, the structure of which differ 

 alternately. 



10. Genus Isis. 



Linnaeus, Syst. Nat., 12th ed., p. 1287, 1767. 



Axal sclerobasis composed of joints, alternately corneous and calcareous ; branches 

 proceeding from the calcareous joints. 



Typ. sp., Isis hippuris, Lin., loc. cit. 



11. Genus Mopsea. 

 Lamouroux, Polyp. Flex., p. 466, 1816. 



Axis presenting the same structure as in the preceding genus, but with the branches 

 proceeding from the corneous joints. 



Typ. sp., Mopsea dichotoma, Lamouroux, loc. cit., p. 467- 



11 



