44 



Character of Alcock's Species. Characters of Caliijunjia wr/ii-Hlata, Pall < 



c. On a centimetre of the twigs there c. On a Centimetre there are only 5 or G 



are 8 to 9 whorls of polyps. whorls. 



d. The length of the contracted polyps d. The length of the contracted polyps 



is 075 mm. or less. is 1 to 1/25 mm. 



e. The distance between the successive e. This distance is 1 to 1/5 mm. 



whorls of polyps generally varies 

 from 0'4 to 0'9 mm. 



Alcock's species is more delicate, with much smaller polyps ; the whorls are 

 more numerous. In the details of the polyps there are also some differences. In 

 C. verticillata the exposed surface of the polyps is covered by four well-developed 

 longitudinal rows of scales, a pair of abaxial and a pair of lateral rows. These last 

 rows are somewhat reduced in Alcock's species, where they are each represented 

 by only three scales, two distal and one basal scale. The inner lateral rows are 

 much reduced in both species. 



The new species may also be easily distinguished from all the dichotomously 

 branched species of Caligorgia hitherto described, viz. C. ventilabrum, C. modesta, 

 and C. compressa ; it is more delicate, with smaller polyps, and none of these three 

 species has so few polyps in each whorl, even on the thinnest twigs. 



There are, however, two new species in the collection made by the Siboga 

 Expedition under the direction of Professor Max Weber in the Malay Archipelago, 

 which in their habit, the dimensions of the polyps, and the small number of polyps 

 in each whorl, much resemble Alcock's species. These are described in my mono- 

 graph on the " Primiioidse of the Siboga Expedition " ; in the present note I can only 

 point out the more important differences between these species and this new species. 



One of them, Caligorgia minuta, is distinguished by the much larger and less 

 numerous scales in the polyps ; the abaxial rows consist of only 5 scales each, against 

 7 in Alcock's species ; and of the outer-lateral rows only one distal scale is left, 

 against 3 scales in Alcock's specimen. The operculum in C. minuta is a much 

 lower cone. 



The other new species, C. similis, very much resembles Alcock's species ; but 

 still it seems to me, so far as I can judge from the small material at my disposal of 

 both species, that they are different. The differences are stated in the following 

 table : 



Characters of Alcock's Species. Character* of C. similis. 



a. The polyps are arranged in whorls of a. The polyps are arranged in whorls of 3, 

 2, less often of .'5. 1 very rarely 2, on the thinner t\\ i-- : 



on the thicker branches the whorls 

 number 4, perhaps also 5 polyps. 

 1 On the larger branches three was the usual number. J. A. T. 



