ACAVUS. 153 



Group of magnified. 



H. magnifica Fer., vi, 65. H. souverbiana Fisch., vi, 66. 



polyzonalis Beck. f. audeberti Mouss., vi, 67. 



Group of goudotiana. 



H. oviformis Grat., vi, 68. H. grandidieri C. & F., vi, 72. 



v. phenax Pils., vi, 69. H. partuliformis Bttg., vi, 72. 



H. goudotiana Fer., vi, 70. H. oomorpha Mab., vi, 49. 

 H. echinophora Fer., vi, 71. 



Group of farafanga, etc. 



H. farafauga Aug., vi, 73. H. gloriosa Pfr., vi, 68. 



farafanganensis C. & F. H. (?) follis Fer., vi, 74. 



Genus ACAVUS Montfort, 1810. 



Acavus MONTF., Conch. Syst., ii, p. 234, type H. hcemastoma. 

 SEMPER, Reisen, p. 9 (anatomy). SARASIN, Ergeb. Naturwissen- 

 sch. Forsch. auf Ceylon, i, 1888 (embryology). BINNEY, Ann.N. 

 Y. Acad. Sci., iii, p. 92 (dentition). Otala (in part) SCHUMACHER. 

 Oligospira ANCEY, Conch. Exch.,ii, p. 22, 1887, types H.waltoni 

 and H. skinneri. 



Shell imperforate, globose depressed or globose-trochoidal, solid, 

 bright colored. Whorls less than 5, rapidly increasing, the several 

 earlier forming the nuclear or embryonic shell, which is about one- 

 third the diameter of the adult. Last whorl deflexed in front. Aper- 

 ture very oblique, the lip vividly colored and broadly expanded; 

 colurnellar margin long, obliquely descending, broadly fattened, the 

 columellar lip adnate. Type A. ha:mastoma, pi. 38, fig. 1. 



Animal with undivided sole, and no pedal grooves ; lung and kid- 

 ney very short, the latter opening at the base of the kidney. Body- 

 lobes of the mantle present, of moderate or small size. 



Jaw strong, low-arcuate, entirely smooth, without median projec- 

 tion. 



Radula having the teeth all unicuspid (pi. 50, fig. 8, 26, A. xkinneri. 

 PI. 50, fig. 5, A. phoenix. PI. 48, fig. 14, A. hozmastoma. 



Genital system having no accessory organs. Penis having termi- 

 nal retractor, the interior with two longitudinal pilasters below, with 

 a very short, imperforate papilla at their base, at the base of which 

 the vas deferens enters. Spermatheca on a very short duct (PI. 50, 



