FROM THE 3JERGUI ARCHIPELAGO. 



129 



Species of Poltzoa from Mergui already recorded # . 



Family Cellulariiile. 

 Scrf/pocellaria, Van Beneden. 



SCRUPOCELLARIA DIADEXIA, Blislc. (Plate XII. fig. 6.) 



The Mergui form agrees, on the whole, with figure 3 (plate 

 xxviii.) in the B. M. Catalogue, and with the figure of S. ciliata, 

 Audouin (=S. diadema, accordiug to Busk), in the ' Challenger ' 

 Report (plate xi. fig. 5) ; but there are differences between them 

 which are worth noting. In the Mergui specimens the lowest 

 spine on each side, when mature, is bifid at the extremity, and 

 I have little doubt that where the spines are perfect this will be 

 found to be a constant feature. The characteristic form of the 

 scutum is shown in fig. 3 of the B.M. Catalogue, and, so far as 

 I have seen, there is little variability in shape, except such as is 

 dependent on the degree of development. The regular rounded 

 outline represented in the 'Challenger' figure is certainly not 

 met with in Mergui examples. The scutum has a rather long, 

 suberect pedicel; the shield is triangular, depressed in the 

 centre, the sides very much elevated, running out into a strong 

 dentate projection, the anterior margin also dentate. The an- 

 terior avicularia are commonly large and more or less elevated, 

 with an elongated mandible pointing obliquely downwards ; 

 sometimes a smaller form occurs. I have seen no approach to 

 the tall columnar form which is represented in figure 1 of the 

 B.M. Catalogue. In the 'Challenger' Report Mr. Busk has 

 referred S. diadema to Audouin's Crisia ciliata; but the identifi- 

 cation is purely conjectural, and can only serve, as it seems to me, 

 to perplex the student. To take a single point, the scutum of 

 Crisia ciliata as delineated by Savigny, which is very definite and 

 peculiar in character, is quite unlike that of S. diadema. 



Family Bicellariidje. 

 Beaxia, Johnston. 

 Bea>~ia mirabilis, Johnston. 



* " Contributions towards a General History of the Marine Polyzoa. — XII. 

 Polyzoa from India (Coast of Burmah)." Ann. k Mag. Nat. Hist. 5tk ser, 

 vol. xiii. pp. 356-3G2. pL xiii. (1884). 



