264 



This species was collected at Station Jedan. As the figure (PI. XXVII, fig. 3) shows, 

 the Cirripedes are attached to a much ramified Alcyonarian Polyp, the name of which I have 

 not been able to make out. 



General remarks. This is a very peculiar species : in the first place it is a 

 Pyrgomd with the opercular valves of a Balanus. In three of the hitherto known species of 

 Pyrgoma [P. conjugatwm^ P. grande and P . monticulariaé) the scuta and terga are perfectly 

 calcified together, and this is also the case with the opercular valves of P. kuri\ in a fifth 

 species (P. millcporaé) these valves are slightly calcified together, the scutum being, moreover, 

 much elongated; the scutum of P. dentatum and P. crenatum is much elongated all the same ; 

 an abnormal long spur — four times as long as the upper part of the valve — characterizes 

 the tergum of P. cancellatum ; sub-triangular scuta and terga, like those of Balanus, occur 

 only in P. anglicnm and P. Stokesi, two species approaching each other closely and both 

 belonging to the Atlantic region. Comparing these valves of P. anglicum with those of P.jedani, 

 we see at once that the scutum of the latter, with its feebly developed ridges and the inden- 

 tation of the basal margin representing the cavity for the lateral depressor muscle, is quite 

 different, and that the spur of the tergum which is well-developed in P. anglicum, can hardly 

 be made out in the new species. 



In the second place, the general shape of the shell and the way in which it is attached 

 to the Alcyonarian is also quite peculiar. In this respect also it comes perhaps nearest to 

 P. anglicum, but nothing can be made out in the new species of the pores which permeate 

 the basis in that species. 



Thirdly, I must point out that its attachment to an Alcyonarian and not to a coral 

 is, so far I know, characteristic for the present species, all the others living, as Darwin says, 

 "imbedded in corals". 



Genus Creusia Leach 



Darwin thought best to describe the different forms of Cirripedes belonging to this 

 genus, not as different species, but as so many varieties of a single species. According to him 

 the variations are local, the greater number of specimens embedded in the same coral resem- 

 bling each other. Of these varieties, to which Darwin has given no names, and of which he 

 distinguished no less than eleven, according to him several inhabit the Malay Archipelago: 

 Java, the Philippines, Singapore, etc. 



This species lives attached to or embedded in corals, and has not been observed 

 hitherto at any considerable depth. It is distributed "throughout the tropical seas" (Darwin); 

 but, partly in consequence of the insufficiency of the available material, our knowledge of the 

 distribution of these different forms is still a very incomplete one. Weltner 1 gives a list 

 of the localities from which the Berlin Museum has received samples of Creusia spinulosa - — 

 but as he does not say to which varieties or forms these samples belong, his list does not 

 enlarge our knowledge very much. 



WELTNER, W., Verzeichnis u.s. w. Archiv f. Naturgeschichte. 1S97. Bd. 1. S. 255. 



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