KEPORT ON THE CIRKIPED1A. 1.*>1 



attachment. The surface of the different corrvpartments is smooth, but it is covered by a 

 mud-like granular substance, which cannot so easily be taken away, and therefore 

 probably is attached to a very thin and rudimentary membrane. The compartments do 

 not show the growth-ridges very distinctly, but the opercular valves do. The interna] 

 surface of the parietes is very strongly ribbed in the lower part. 



The radii arc very narrow, their sutural edges arc smooth; their summits very 

 oblique and rounded; the ahu arc rather broad, and have the summits not oblique bul 

 straight, and parallel to the basis of the shell ; the alse extend only very slightly above 

 the level of the opercular membrane. The parietal tubes are very narrow ; in the upper 

 part of the walls they are filled up and solid. The basis is very thin, the layers which 

 compose it are extremely thin and fragile ; the tubes of. the base run radially outwards 

 from the centre to the periphery of the base ; the tubes are extremely narrow, and as tic- 

 base is too thin to permit of a transverse section, the presence of the tubes is always 

 to a certain degree problematic. 



The scut ma is triangular, its occludent margin is slightly toothed, which is caused by 

 the projection of the growth-ridges. The articular ridge is not very prominent, but it 

 extends rather far downwards; the adductor ridge is hardly visible, the pit for the lateral 

 depressor muscle and that for the adductor muscle are both very flat. The tergum is 

 well characterised by the length of the basal margin, which surpasses that of the 

 scutal margin; the two parts into which the basal margin is divided by the spur form 

 together a straight line. The spur is short, broad, and bluntly truncated. The carina! 

 margin is arched ; the crests for the depressor muscle are very distinct. The articular 

 furrow is not very deep, but distinct. The apex is not at all beaked. 



Of the body of the animal I cannot give many details. In two specimens I opened I 

 found the body shrivelled, so as to be unfit for close inspection. For want of material 1 

 could not sacrifice more. The mouth has a labrwm with three well-developed and sharply- 

 pointed teeth on each side of the notch, and with elongate palpi covered nearly all over the 

 surface with very long hairs. The mandibles have only five (four, but one was broken off) 

 blunt teeth, the maxilla have the edge straight, without any notch, and armed with seven 

 broad spines of nearly equal size, the first two being slightly stronger, besides numerous 

 slender hairs. The second maxilla* are remarkably elongate. The cirri of the first pair 

 have two very unecpial rami. 



This species was taken in the Arafura Sea, at Station 188, September 10, 1874 ; lat. 

 9° 59' S., long. 139° 42' E. ; depth, 28 fathoms; bottom, mud. 



Observations. — This species has, I believe, not a single near relation among the other 

 species of the section C. On the other hand, I think it resembles much the Balanus 

 glandula, Darwin, a species belonging to the section D. In most respect-, however, it 

 differs slightly even from this species, and I think, as there can hardly he doubl as to 

 the porosity of its base, it is safest to place it in the section C. 



