MUSEUM OF COMPARATIVE ZOOLOGY. 21 



Family CHRYSOGORGID^ Verrill, nov. 



Coral variously branched, the branches most commonly taking a spiral ar- 

 rangement. Axis partially calcareous, generally with a brilliant iridescence 

 and metallic lustre. Base, in most of the species where it has been observed, 

 calcareous, and divided into irregular, divergent, root-like processes for anchor- 

 ing in tlie mud, but in some species it is flattened and adherent to pebbles. 

 Usually the hard, white calcareous base is sharply contrasted with the axis of 

 the stem. The calicles are prominent, scattered along the branches, either 

 standing at right angles or obliquely; they are covered with moderately large 

 elongated or flat spicula, and are usually eight-lobed at the summit. Coen- 

 enchyma very thin, with oblong or elongated spicula. 



This family includes some of the most beautiful and interesting of all the 

 known Gorgonians. These species are remarkable both for the elegance of the 

 forms in which they grow, and for the brilliant lustre and opaline and irides- 

 cent colors of the axis, which in some species has the bright emerald-green 

 lustre of the most brilliant tropical beetles, and in others is like burnished 

 gold or polished mother-of-pearl. 



The known species are all inhabitants of deep water, and all are from the 

 West Indian seas, except Dasygorgia Agassizii, which occurs off" the New Eng- 

 land coast. The observed species can be referred to the following genera. 



A. Much branched, often spirally; the branches repeatedly forking. 



Clirysogorgia. Calicles elongated, often narrowed near the base, covered with 

 rather long rough spicula, which are more or less transverse over the basal 

 half, and curved to fit the surface. Spicula of the coenenchyma elongated 

 or fusiffjrm, warted. 



Dasygorgia. Calicles obliquely placed on the branches, swollen at base, cov- 

 ered with flat, oblong spicula, which are arranged longitudinally or ob- 

 li([uely. Spicula of the ccenenchyma oblong or scale-like, nearly smooth. 



AA. Axis forming a spiral or helix, with slender undivided branches, in a single 



spiral row. 



Iridogorgia. Calicles verruciform, with swollen bases extending along the 

 branches, filled with slender elongated spicula, obliquely and transversely 

 arranged. Spicula of the ccEnenchyma similar. Surface of ccenenchyma 

 with peculiar soft verrucse. 



Although but one species (Dasygorgia Agassizii) has been found on our coast 

 north of Florida, I have included here some of the West Indian forms for the 

 sake of comparison, and more fully to illustrate the characters of this hitherto 

 imperfectly known group. 



This family is related, in several respects, to Primnoidae, especially to Calli- 

 gorgia and allied genera, which are likewise chiefly found in deep water, and 

 some of which have the axis similar in structure and lustre. In the latter 

 group, however, the calicles are differently constructed, and the spicula be- 



