2Ó2 



It is, moreover, the first instance of a species of Pyrgoma being found at a somewhat 

 considerable depth. 



3- Pyrgoma jedani n. sp. PI. XXVII, fig. 3 — 8. 



Shell irregularly conical, orifice oval, with a somewhat swollen border-, basis irregularly 

 cup-formed and attached to the surface of the ramifications of an Alcyonarian ; scutum and 

 tergum triangular, not calcified together; spur of tergum feebly developed. 



Of this very interesting new species (PI. XXVII, fig. 3), numerous specimens are atta- 

 ched to an Alcyonarian from Station "Jedan". They look as if they formed one organism 

 together with the Alcyonarian ; the smaller specimens of the Cirripede especially can hardly be 

 distinguished from swollen parts of the branches of the Alcyonarian. The large specimens have 

 their surfaces also quite merged into that of the organism to which they are attached, and the 

 ramifications of the latter seem to loose themselves in the surface of the Cirripede. 



Some of the Cirripedes are attached to one another, and in this state have a very 

 irregular shape. Most specimens show more or less distinctly a somewhat laterally flattened 

 conical shell and an irregularly cup-formed basis. Where shell and basis unite, a more or less 

 prominent border or margin can be distinguished, and, in some of the specimens, rims or lists 

 run from that border to the orifice of the shell. This orifice is moderately large and has a 

 swollen border, which is distinctly divided into parts or lobes in some of the specimens. In 

 several specimens, more or less deep furrows extend over the surface of the shell, parting from 

 the orifice, and dividing the shell into parts which at first sight might be compared with the 

 compartments of other sessile Cirripedes. The surface is irregular, moreover, through the presence 

 of numerous tubercles or knobs, which, however, are also much more numerous and prominent 

 on some of the specimens, than on the others. 



The opercular valves are not calcified together and, in many regards, resemble those 

 of Ba/anus. The scutum (PI. XXVII, fig. 4, a and c) is rather thick, triangular, with the 

 apex pointed but not produced, and with the basal margin distinctly curved ; the articular ridge 

 is strongly developed and extends to the basi-tergal angle of the valve; the part of the valve 

 along the tergal margin is distinctly reflexed. This is also the case with the part of the valve 

 along the occludent margin. The inner surface of the valve is almost perfectly smooth, 110 

 tracé of an adductor pit or adductor ridge being visible; a lateral depressor pit, however, can 

 be seen at the basi-tergal corner of the valve. The outer surface of the scutum shows pro- 

 minent growth-ridges; the whole valve is not flat, but distinctly bowed along a line extending 

 from the apex to a point near the middle of the basal margin. 



The tergum (PI. XXVII, fig. 4, b and d) is almost quite flat, thin, triangular. lts 

 apex is rounded and not beaked; growth-ridges on the outer surface very indistinct. The scutal 

 margin is nearly straight, the carinal bowed, the basal sinuous. The spur is only feebly devel- 

 oped and represented by a part with rounded circumference which projects a little beyond 

 the basi-scutal angle of the valve. On the inner side the growth-ridges are slightly more 

 distinct than on the outer surface. There is a slightly-prominent articular ridge and furrow, 



134 



