THOMSON AND EUSSBLL— AXIFEEA. 141 



Acamptogorrjia cei/lo)wnsts has a strilcing resemblance in colour and habit to Murkella 

 ^nivjiurea, which is generally found along with it, but the two genera are not nearly- 

 related. Similarly, Acamptogorgia gracilis is like a mimic of Muricella rubra, and both 

 these species are somewhat like a straggling variety of Siphonogorgia mirabilis, 

 Klunzinger, which has white polyps. 



(r/) Of the genus Acis, the collection has a rich representation (eight species), and we 

 have taken this opportunity of working out an artificial key. Of all the species, the 

 most striking is Acis dejecta, sp. n., whicli spreads out horizontally, has the polyps on 

 the sides and under surface of the branches, and has large superficial scales. In Aclfi 

 obscura, sp. n., which is a much less specialized species, like an Acis in the making 

 indeed, we found a useful instance of the way spicules differ according to the age and 

 vigour of the colony. This species is furthermore of systematic interest in showing that 

 the genera Acis and Muricella are nearly related. 



(/(.) In the numerous specimens of IluriceUa complanata, "Wright and Studer, there is 

 a fine illustration of colour- variability ; white, yellow, pale pink, rose, and other hues 

 are seen. 



(^) Considerable time was spent in examining numerous apparently diff'erent Govgo- 

 nellids of the Jtmcella type, with the result of showing that no importance can be paid 

 to the number of rows of polyps, or to the degree of projection of the polyps, or to the 

 colour. 



Tamily Lasygorgidae. 



Genus CHRYSOGQRGIA. 



1. Chrysogorgia orientalis, Versluys. 

 Por description see : — 



Versluys, J. : '•' Die Gorgoniden der Siboga-Expedition. II. Die Chrysogorgiidae." Siboga-Expe- 

 ditie. Monographie xiii." 1902, pp. 53-55, 5 figs. 

 A somewhat damaged specimen seems nearer to C. orientalis, Versluys, than to any 

 other species. 



Locality. Saya de Malha (C 20) *, 300-500 fms. 



Previously recorded from Ceram Sea, 924 metres, and Timor Sea, 918 mQive?, {Versluys, 

 1902); and from the Indian Ocean, 6° 32' N., 79° 37' E., 675 fms. [Thomson and 

 Kenderson, 1906). 



Pamily IsidSB. 



Genus C ERATO ISIS. 



2. Ceratoisis sp. 



A small piece of a Ceratoisis, 2 cm. in length, with the ccEnencliyma much worn and 

 very fragmentary. It is not possible to determine the species with certainty, but the 

 spicules are smooth rods and broad spiny spindles, a feature which suggests that the 

 specimen may belong to Ceratoisis palmce, Wright and Studer. 



Locality. Mauritius, 100-200 fms. 



* These refer to the dredgings made by the expedition at each locality. See Gardiner and Cooper's " Description 

 of the Expedition,'' Trans. Linn. Soc. ser. 2, Zool. vol. xii. (1907) pp. 1G3-169. 



19* 



