OKTHALICUS. 



Subgenus CORONA Albers, 1850. 



A Soutli American group of rather large, solid, lengthened spe- 

 cies, either dextral or sinistral, the colunella more or less truncate' 

 or excised at base, twisted and bearing a callous fold above. Soft 

 anatomy unknown. Type L. regina, Fer. 



Corona is considered by Mr. E. A. Smith to be more nearly re- 

 lated to the group of Metorihalicus atramerdarius than to Liguus. 

 Of. Proc. Malac. Soc., v, p. 170. 



L. regina Fer., xii, 177. L. incisus Hupe, xii, 179. 



A. melastoma Swains. L. regalis Hupe, xii, 180. 



A. melanostoma Gray. regina auct. 



0. rex dextrorsus^Sk. v. loroisianus Hupe, xii, 183. 



L. perversus Swains., xii, 178. L. pfeifferi Hid., xii, 146. 



0. rex sinistrorsus Bk. v. gracilis E. A. Sm., 1902. 



Subgenus HEMIBULIMUS Martens, 1885. 



Fusiform, dark-colored, with obtuse apex, the first whorl finely 

 wrinkled. Columellar margin concave, distinctly truncated at base. 

 The jaw (pi. 56, fig. 50) is composed of 13 imbricating plates, the 

 median one reaching the basal margin. Radula with 62.2.1.2.62 

 teeth. The centrals are much lengthened, with a long, lanceolate 

 mesocone and v estigeal side cusps. Two laterals on each side are simi- 

 lar, but asymmetrical. The rest of the teeth are short and broad, 

 with quadrate base, very wide, short cusps, and a minute ectocone. 

 The outermost marginals become tricuspid (pi. 56, figs. 51, 52, 53). 



L. magnificus Pfr., xii, 185. Andes of Colombia. 



v. excisus Mart., xii, 185. 



Genus ORTHALICUS Beck, 1837. 



Man. Conch, xii, p. 186. Strebel & Pfeffer, Beitr. Mex. Land-'u. 

 Siisswasser-Conchyl., Theil v, p. 2 (anatomy of 0. sultana). W. G. 

 Binney, Ann. Lye. N. H. of N. Y. xi, p. 38 (anatomy). 



In 0. sultana from Guiana, Strebel found the right neck-lobe of 

 the mantle strongly developed ; the left forms a continuous rim 

 around the entire mantle. The genital system (pi. 55, fig. 43) has 

 the general characters of other genera of the sub-family, except that 

 the appendix of the penis is represented by a circular swelling. The 

 latter was not noticed by Binney, who examined a specimen from 

 Maranon, Peru. 



