THE SESSILE BARNACLES. 307 



ORIENTAL SPECIES. 



CHTHAMALUS CHALLENGERI Hoek. 



Plate 72, figs. l-4r/. 



18S3. Chth amalus challcngcrl HOEK, Challenger Reports, Zoology, vol. 8, 



p. 1G5, pi. 13, figs. 35-38. 

 1911. Chlhanwlus cluillcnyrrl Hoek, KRUGEIJ, Beitriige ziir Cirripedienfauna 



Ostasiens, p. 46, pi. 3, fig. 30. 



Distribution. Japan ; Matsushima. 



The barnacle has rounded ribs, rather strong, white throughout, 

 rot corroded, and smooth inside. The radii are very narrow. Carino- 

 rostral diameter 7.6 mm. 



The scutum is lengthened. Articular ridge prominent, its edge 

 bisinuate, being excavated above, tapering below the median promi- 



FIG. 87. CHTHAMALUS CHALLENGED, MATSUSHIMA. o, MANDIBLE. 1), MAXILLA, c, TERMI- 

 NAL SEGMENT OF THE SHORTER UAJIUS OF CIRRUS II. (I, SEVENTH SEGMENT OF CIRRUS VI. 

 C, INTERMEDIATE SEGMENT OF CIRRUS VI OF THE VARIETY FROM AYUKAWA, JAPAN. 



nence. Adductor muscle pit small and rather deep, with a raised 

 rim forming a strong adductor ridge. Lateral depressor muscle pit 

 is very indistinct. 



The tergum is wide above, narrow below. Upper free portion con- 

 spicuously laminate. Articular ridge strong, the articular furrow 

 wide. There is no real spur, as the basiscutal angle is terminal. 

 The basal margin is deeply sinuated below the depressor muscle crests, 

 the strongly developed crests being borne on a triangular lobe of the 

 valve, as in many other species. 



The mandible is of the stellatus form, but the three points at the 

 lower extremity are much more strongly developed and the finely 

 pectinated space above them is shorter (fig. 87). 



