164 THE VOYAGE OF H.M.S. CHALLENGER. 



Subfamily 2. Spongiodermin^. 



Genus Iciligorgia, Duchassaing, emend. Ridley. 



? leiligorgia, Duchassaing, Eevue des Zoophytes des Antilles, p. 12, 1870. 

 Iciligorgia {emend.), Ridley, Rep. ZooL CoU. H.M.S. " Alert," p. 351, 1884. 



In Ridley's account of the Alcyonaria found during the voyage of H.M.S. "Alert" 

 in the Indo-Pacific Oceans, he adopts Duchassaing's genus Iciligorgia for a species 

 found in Torres Strait. A specimen of Ridley's species {Iciligorgia orientalis) is in the 

 Challenger collection from the same locality, but it seems to' us a matter of doubt 

 whether this species be rightly referred to Duchassaing's genus, which was made for a 

 species {Iciligorgia schrammi) found at Guadaloupe. 



Duchassaing's diagnosis is as follows — " Axis mollis, spongiosus, spiculis farctus ; 

 cortex tenuis, spiculis aciniformibus formatus ; calycibus mammseformibus, obtusis, in 

 utroque latere ramorum uniseriatis. Genus situ Polyporum, axe corticeque interse 

 distinctis, a Briareis recedens, Polypis utroque latere uniseriatis, a Paragorgiis diag- 

 noscitur." 



To this is added that the " circulatory canals " are as in Briarea and that the 

 Gorgonia {Titanideuvi, Verrill, 1864) suberosa of Ellis is closely allied thereto. 



. No specimen of this genus exists in the museum at Turin, but we think it better to 

 accept the genus, as emended by Ridley, leaving it to future investigations to determine 

 the question as to whether it is identical or not with that described by Duchassaing. 



Iciligorgia orientalis, Ridley (PI. XXX. fig. 2). 



Idligm-gia orientalis, Ridley, loc. cif., p. 351, pi. xxxvii. figs. F, F"; pi. xxxviii. fig. e. 



The specimen in the collection consists of what appears to be but a portion of a 

 colony. What seems to be its main axis is about 230 mm. in height, with a basal 

 diameter of 17 mm., tapering in the branches to one of from 2 to 3 mm. The 

 branching is very irregular, though with a decided unilateral tendency. Possibly owing 

 to the strength of the spirits in which the specimen was preserved, the coenenchyma 

 is somewhat contracted and wrinkled. The main stem is flattened in outline, being 

 17 mm. long by 8 mm. wide, but the terminal tips of some of the branches are nearly 

 circular. 



The polyps are found scattered irregularly over the surface of the stem and branches, 

 sometimes solitary, and very slightly prominent ; at other times and more frequently in 

 narrow clefts of the coenenchyma, with lip-like edges, between which the polyps are 

 completely retractile ; these are the " knife-like " edges of Ridley, but in the Challenger 

 specimen they are not exclusively confined to the lateral margins of the branches ; 

 sometimes even three such wavy, linear slits will be found on a single branch. 



