178 COSTELLARIA. 



T. CATENATA, Swainson. PL 53, fig. 515. 



White, with large irregular chestnut-brown spots, arranged in 



bands. Length, *5 inch. 



Me of An/t<i, Polynesia. 



An obscure shell, probably not adult. 

 T. LILACINA, Sowb. PL 53, fig. 516. 



Shell finely decussated ; ash color, lighter at the suture. 



Length, -6 inch. 



Habitat unknown. 

 T. MARMOREA, A. Ad. PL 53, figs. 517, 518. 



Olivaceous, marked with reddish brown ; longitudinally eostatr . 

 costse thick, subnodose above, interstices with revolving striae. 



Length, '5 inch. 



Isle of Negros, Philippines ; coarse sand, ten fathoms. 



Sowerby's two illustrations, the only figures of this species 

 heretofore published, and which I cop}-, appear to represent two 

 different species. 



T. ARRACANENSIS, Sowb. PL 53, figs. 519. 

 Brown, with a median white line, ribs lighter colored. 

 Length, '65 inch. 



Arrac0n. 

 T. CREBRILIRATA, Reeve. PL 53, figs. 521-526, 530. 



Light chestnut or olive, tops of ribs lighter, with usually a 

 narrow central brown band, and a superior white line ; ribs 

 narrow, interstices with close revolving striae. 



Length, 1 '25-1 "75 inches. 



Indian Ocean; Japan; Philippines ; Polynesia. 



Reeve hesitated to describe this as a distinct species from his 

 M. polita, to which, he says, it bears the same relation that the 

 ribbed does to the smooth variety of M. ebenus-, I venture, 

 nevertheless, to locate the two species in distinct groups. I do 

 this, whilst expecting that Reeve's suspicion of their identity 

 will be confirmed, as it is a case paralleled by many others in 

 this genus, all pointing to the evanescent nature of the sculpture 

 and patterns of coloring. In fact, unless we set up an artificial 

 standard for the separation of species, in some genera, we should 

 have no species remaining, to speak of. T. rosea, Kiener, not 

 Duclos (fig. 522), T. tenuilirata, Sowb. (fig. 523), T. rubricata, 

 Reeve (fig. 524), T. subtruncata, Sowb. (fig. 525), T. Layardi, 



