MOLLTTSCA. I ( .) 



twice as many, and produce a denticulate margin to the valves. 

 Interior slightly iridescent. Umbones small, glossy, not radiately 

 sculptured like tho rest of the shell. Length <> millim., height 3|-, 

 diam. 3. 



lliih. Dundas Straits. 



This is a very prettily sculptured species, approaching, as regards 

 outline, M. vartcosa. It is, however, quite distinguishable by the 

 greater coarseness and subgranular character of the radiating ante- 

 rior and posterior ridges. 



The single specimen described above may not be full-grown ; but 

 I conjecture it never attains a much larger size. 



53. Modiolaria varicosa. (Plate VII. figs. M,M1.) 

 Gould, Proc. Bost. Sue. Nat. Hist. 1861, vol. viii. ; Otia Conch, p. 176. 



Hah. Port Jackson (Coppinger) ; Sydney {Gould). 



This pretty little species was figured by Peeve (Conch. Icon. fig. 83) 

 as the young of Modiola strigata, Hanley ; and this must have in- 

 duced Gould to observe that it " is marked like" that species, for 

 in reality there is very little resemblance in the painting of the two 

 shells. The radiating scrdpture is faintly indicated in the above 

 figure by means of scratched lines, but these are only noticeable 

 under a lens. 



54. Lithodornus teres. 



Modiola teres, PhUippi, Abhild. vol. ii. p. 148, pi. 1. fig. 3. 

 Lithodornus teres, Peeve, Conch. Icon. fig. 13. 



Hub. Pacific Ocean (Phil.): Philippine Islands (Cuming); Port 

 Denison, Queensland (Coppinger). 



The anterior perpendicular strise are rather coarse in this species ; 

 the raised interstices between them are very conspicuous at the 

 margin, and gradually become finer as they ascend the valves, some- 

 times furcating at one or more of the concentric lines of growth. 

 The interior is pinkish or bluish, and more or less iridescent. 



55. Area navicularis. 



Bruguiere ; PhUippi, Abbild. vol. ii. pi. 3. fig. '2; Peeve, Conch. Icon. 



fig. 70 ; Wood, Index Test. pi. 9. fig. 5. 

 Var.=Arca linter, Jonas, PhUippi, I. c. fig. 1. 

 Var.=Arca subquadrangula, Dunker, PhUippi, I. c. fig. 3. 

 Var. = Area cunringii, Dunker (MS. in coll. Cuming ) ; Adams, Genera 



Moll. ii. p. 533. 



Hab. Port Molle, Queensland ( Coppinger) ; Port Phillip, China, 

 Cape Capricorn, Amboina (Brit. Mus.). 



The varieties respectively called A. linter and A. subquadrangula 

 are distinguished only by very variable characters, snch as form and 

 the amount of ligament, which in this group of Arks are of little 

 value. 



