154 PYROCHILUS. 



fig. 1, A. skinneri. Fig. 3, A. hcemastoma). Eggs very large, oval, 

 hard shelled (pi. 50, fig. 4, A. phoenix, natural size). 



The section Acavus comprises Ceylonese Helices of large size and 

 superb coloring. The shell is capacious, with a broad, polished lip 

 of vivid red, lilac, or intense black hue. The young shells at the 

 time of their extrusion from the egg are bright colored, with round 

 periphery, and are about one-third the size of the adult. The teeth 

 are all unicuspid, but the marginals have shorter cusps than in Heli- 

 cophanta or Panda ; and the shell differs from these groups in its 

 broad colurnellar lip and brilliant coloring. They are arboreal in 

 habit. 



Group of A. hwmastomus. 



A. hsemastomus L., vi, 78. A. prosperus Alb., vi, 80. 



v. melanotragus Born., vi, 79. A. phoenix Pfr., vi, 80. 



v. conus Pils., vi, 79. A. superbus Pfr., vi, 81. 



v. concolor, Pils., vi, 303. v. roseolabiata Nev., vi, 82. 



A. fastosus Alb., vi, 79. v. grevillei Pfr., vi, 82. 



Group of A. valtoni (Oligospira). 



A. valtoni Rve., vi, 83. A skinneri Reeve, vi, 84. 



waltoni auct. 



Genus PYROCHILUS Pilsbry, 1892. 



Phania ALB., Die Hel., edit. Martens, p. 157, type H. lampas. 

 MARTENS Landschn. der Ostasiat. Exped., p. 325. PILSBRY, Man. 

 Conch., vi, p. 193. Not Phania Meigen, Syst. Beschreib. Eur. 

 zweifliigel. Insekten, iv. p. 218, 1824,Pyrochilus PILSBRY, Proc. 

 Acad. Nat. Sci., Phila., 1892, p. 391. 



Shell large, solid, imperforate, depressed ; keeled at the periphery, 

 at least in the young ; convex above and below, unicolored. Junc- 

 tion of nuclear shell ivith the after-growth not distinct. Lip expanded, 

 bright colored ; columella widened into a flat plate, adnate over the 

 umbilicus, its inner edge blade-like. Whorls about 4. Type P. 

 pyrostoma (see pi. 38, figs. 2, 3, P. lampas). 



Jaw of H. pyrostoma smooth, weakly arched, without median pro- 

 jection. Animal without caudal gland or mantle lobes. Internal 

 anatomy unknown. 



A group of handsome, large helices, all of which are still rare in 

 collections. The brilliant coloring of the peristome and the widened. 



