•2(SG THE VOYAGE OF H.M.S. CHALLENGER. 



The locality of this species has not been hitherto recorded. The most slender ribs 

 are a few just in front of the centre of the valves, those on the anterior end being rather 

 stouter but not so thick as those down the posterior angle. Between the ribs are fine 

 concentric lirse which connect them and produce a slightly nodulose appearance and 

 somewhat crenulated edges. The interior of the valves is white, with the exception of a 

 small portion in the umbonal region, which is yellowish. 



Area (Scapharca) clathrata, Reeve. 



Area clathrata, Eeeve, Conch. Icon., vol. ii. ]>!. vii. fig. 48. 

 Habitat. — Torres Strait, in 3 to 11 fathoms; and Amboiua, in 15 to 25 fathom.-; 

 (Challenger); Islands of Burias and Ticao, Philippines (Eeeve). 



The ribs in this species are about twenty-five in number, rather sharply cut at the 

 sides, and sej^arated liy deepish grooves. It is very closely related to Area radiata, 

 Reeve. The three small valves from Torres Strait are more like the t}"pes as regards 

 form than the single specimen from Amboina, which is narrower behind and more arcuate 

 below. 



Area {Seapharca?) consociata, n. sp. -(PI. XVII. figs. 7-7o). 



Testa ArccB clathratoe similis, sed costis tuberculis minoribus et rotundatioribus 

 ornatis, lineis incrementi in interstitiis magis remotis et curvatis, umbonibus in medio 

 hand impresse radiatis. 



This species is very like Area clathrata, Reeve, in general aspect, but is, I believe, 

 distinct. The valves have no impressed ray near the beaks, the raised lines of growth 

 between the ribs are more curved and somewhat further apart than in Reeve's shell, and 

 the nodules are smaller, not so broad as the costaj, and more raised like minute half-beads. 

 At each end of the hiuge-line, and parallel with it, are two or three short, raised lines at 

 right angles to the teeth, which do not exist in Area clathrata. 



Length 12^ mm., height 9|, diameter 8^. 



Habitat. — Station 189, Arafura Sea, in 25 fathoms ; green mud. 



The above dimensions do not probably represent the full size attained by this pretty 

 species. 



Area {Seapharca) gubernaculum, Reeve. 



Area gnbenmmlum, Eeeve, Conch. Icon., vol. ii. pi. iii. fig. 14. 

 Area clmhnnthum, Eeeve, loc. cit., pi. vii. fig. 4-3. 

 Area luzonica, Eeeve, loc. eil., fig. 44. 



Habitat. — Port Jackson, in 2 to 10 fathoms. 



