192 A DESCRIPTIVE CATALOGUE OF THE 



G. B. Sowerby, Jun., in the "Thesaurus Conchyliorum," 1844, Part IV., con- 

 taining ninety-four species, indicates ten species from the West Indies, of which 

 eight are new. 



In the present paper are enumerated forty species, of which eighteen are new 

 and three for the first time identified as West Indian. 



Synopsis Familiae Scalidarum Indiarum occidentaHum. 



Fam. SCALID^. 



Gen. ScALA, Klein (Scalaria, Lam.). 



Sect. *. Aciona, Leach. 



1. ScALA KREBSii, Morch, n. sp., PI. 29, figs. 1 and 2. 



T. nmbilicata, ovata, polita, striis spiralibus aeiculatis irregulavibus ; striae increment! obso- 

 letissimae; anfr. disjuncti ad suturara angulato-plani, convexi ; costse x in anfr. ult. ad 

 snturum auritse: apertura subcircularis, labio subreflexo. Color albas, in media parte anfr. 

 pallide ferrugineus. 



Long. It mm.; lat. 10^ mm.; alt. aperturse 6 mm. 



Analogue of Scala subpretiosa, BIv. (Sc. pallasii, Kien.) Sowb. Thes. Conch. 

 1844, fig. 14; but the new species is much smaller. 



Hab. St. Thomas "60' bl. S. Mud." H. Krebs (fig. 1), St. Martin, spm. juvenile 

 (H. Krebs, fig. 2). 



2. ScALA PRETiosuLA, Morch, n. sp. 



T. perforata, oblongo-ovata, lactea, politissima ; striae incrementi argutse, obsoletissimae ; anfr. 

 omnino disjuncti, sutura biante ; costae viii in anfr. ult. compressae, candidae, foliaceae, obso- 

 Ictissime crispatffi, suturam versus expanse costae 6 ult. antecedenti oblique adnatse, caeterte 

 continuae; apertura ovalis (sed. fracta in spm.). 



Long. 11^ mm.; lat. 6j mm.; alt. aperturae 4 mm. 



Hab. St. Martin (H. Krebs), two specimens; the smallest is 6 mm. long and 

 4 mm. broad. 



Scala fas data, Sowb., most nearly resembles this species. The whorls are com- 

 pletely separated, rendering the umbilicus visible through the sutural opening. 

 . The ribs are foliaceously dilated at the suture, touching the corresponding rib of 

 the preceding whorl, but the last six ribs obliquely, giving the appearance of 

 being alternate. 



