APPENDIX TO ALCYONAEIA. 



173 



specimen from the Ceylonese collection and another from the Indian Museum 

 collection (see Part III., p. 289). He regards them as representatives of two new 

 species, distinct from von Koch's, and closely related to a new species (C. similis) 

 which will be described in Versluys' memoir on the Primnoidae of the "Siboga" 

 Collection. In the "Siboga" material he found that the number and arrangement 

 of the sclerites in the polyps afforded a constant and reliable basis for specific 

 diagnosis. 



We have therefore to withdraw the remarks we made on the geographical 

 distribution of Primnoa ellisii (= Caligorgia verticillata), and we have to record from 

 Ceylon the new species Caligorgia versluysi, the particular features of which are 

 discussed in the following note which Dr. Versluys has generously supplied : 



Note by Dr. Versluys. 



" I find that the Primnoid collected by Professor Herdman at Ceylon is not referable 

 to Primnoa ellisii, von Koch. As it seems to me that von Koch was not justified in 

 separating his species from Caligorgia verticillata (Pallas), I shall use the older 

 name in comparing it with Heruman's species.* 



The Ceylonese species is decidedly more delicate than C. verticillata, and the type 

 of ramification is different. The more important differences are stated in the following 

 table : 



1. Characters of Herdman's Species. 



(a) The colony is dichotomously branched. 



(/<) The polyps are arranged in whorls of 3 and 



occasionally of 2 ; no higher number was 



observed. 



(') On a centimetre of the twigs about 8 whorls of 



polyps are found. 

 (il) The length of the contracted polyps is less than 



- 75 millim. 

 {") The distance between two successive whorls 



generally varies between 6 millim. and 



' 75 millim. ; sometimes, however, it rises 



up to 1 millim. 



Of the 8 longitudinal rows of scales, which formed the covering of the polyps in 

 the typical primitive Primnoinse, viz., a pair of adaxial, inner lateral, outer lateral 

 and abaxial rows, only four rows, the abaxial and outer lateral pair, are well developed 

 in both species. The inner lateral rows are each reduced to a single large distal 



* Compare Versluys, ' Primnoidae ; " Siboga " Expeditie, Monograph XIII,' second part, which is in 

 the press. 



2. Characters of Caligorgia verticillata. 



(.) The colony is pinnately branched. 



(b) On the thinnest twigs the polyps are arranged 



in whorls of 3, very rarely of 2 ; on the 

 thicker branches the whorls mostly consist 

 of 4 polyps. 



(c) On a centimetre there are only 5 or 6 whorls. 



(d) The length of the contracted polyps is 1 millim. 



to 1 25 millims. 



(e) This distance is 1 millim. to 1"5 millims. 



