168 Mr. G. B. Sowerby on 



circularis, mediocriter latus. Apertura circularis ; peristoma 

 simplex. 

 Alt. 2±, lat. 2| mm. 



Hah. Bitter Lakes, near Suez. 



A little white shell of a globular form, acute at the apex, 

 the first whorls being tinged with light brown. In the 

 absence of the operculum I cannot be quite sure of the 

 generic position of this species, but think T have placed it 

 correctly. 



Pecten (Chlamys) scabricostatus, sp. n. (PI. X. fig. 14.) 



Testa aequivalvis, sequilateralis, teuuicula, suborbicularis com- 

 pressiuscula, supra peracuta, infra rotundata ; auriculis valde 

 insequalibus, sinistra lata, acutangulata leviter squamosa, dextra 

 multo brevior, rectangularis, valvasinistra leviter convexa, undique 

 augustissime radiatim lirata, costis 18-20 rotuudatis, crassi- 

 usculis, aliquis breviter erecte squamatis radiata. 



Alt. 55, lat. 50, crass. 16 mm. 



Hah. Swan River, West Australia. 



About fifty years ago a considerable number of shells of 

 this species came to London, and were distributed under 

 various names, such as senatorius (Gmel.), gloriosus (Reeve), 

 prunum (Reeve), &c. ; but I have always considered the 

 identification, to say the least of it, quite unsatisfactory. The 

 species differs from all the varieties of senatorius (including 

 those bearing the two last-mentioned names) by its broader 

 and less numerous ribs, some of them bearing a few erect 

 prominent scales, a character which at once catches the eye, 

 as they only appear generally on every fourth rib, the others 

 being nearly smooth or having only very small inconspicuous 

 foliation. 



The colours, as in P. senatorius, are vei*y varied ; the shell 

 1 have selected as type is light brown at the upper part, and 

 the remainder pink, while some are plain yellow all over ; 

 others again are mottled with brown, yellow, and white. 



The dimensions given are about the average. The largest 

 of the ten specimens before me measures 68 X 65 and the 

 smaller 40x36 mm.; but I have seen one magnificent 

 specimen of a beautiful clear yellow colour throughout and 

 measuring 78 mm. This shell belonged to the collection of 

 ths late S. I. Da Costa. 



Volsella compta, sp. n. (PI. X. fig. 10.) 

 Testa oblonga, tenuis, vivide purpurea, epidermide tenuis leviter 



