152 DOLABELLA. 



aaa. Shell wider, irregularly triangular, the spire calloused. 



b. Integument of body bearing conspicuous tubercles or 

 foliations ; posterior area with fringed boundary. 



c. Conspicuously spotted or blotched, teremidi, hasseltii. 



cc. Uniform or nearly uniform green, scapula. 



bb. Integument smoothish or somewhat warty ; boundary of 



posterior area simple, ecaudata; californica. 



(D. hemprichii and D. guayaquilensis are omitted from the above 



table). 



D. GIGAS Rang. PL 65, figs. 4, 5, 6. 



Length as much as 30 cm. Violet and gray, with conic simple 

 warts rounded at their summits. 



Shell large and solid ; convex, but with a wide curved depres- 

 sion near each edge outside; very pale buff outside, porcelain-white 

 within; shining and sculptured with strong concentric wrinkles on 

 both sides ; sinus narrow and deeply curved, its edge broadly flaring 

 backward, and with an extremely narrow reflexed margin. Spire 

 well curved inward, with a rounded lump of callus at the apex within. 

 Upper curve of the spire bearing a very large, thin, erect, saucer- 

 shaped accessory callous plate. Cuticle broadly reflexed across the 

 back of the spire, and continued in a wide, tapering reflexed border 

 down the convex margin of shell. Length 80, breadth 55 mill. 



Reunion (t)esh.) ; Mauritius (Lienard, Mobius) ; Red Sea (Cum- 



Aplysia gigas RANG, Hist. Nat. Aplys., p. 48, pi. 3, f. 4. Dola- 

 bella gigas SOWB., Conch. Icon., xvi, pi. 1, f. la, b. MART, in 

 Mobius' Mauritius, p. 306. DESK., Moll. Re"un., p. 53. 



This is the largest species of the genus, and is very readily distin- 

 guished from all others by the broad saucer-like accessory plate aris- 

 ing from the upper margin. The soft parts are known from spec- 

 imens collected by Mobius, and briefly described by von Martens, 

 but not yet figured. 



D. SCAPULA Martyn. PL 26, figs. 26, 27, 28 ; pi. 27, figs. 29, 30. 



Length 30 to 38 cm. Much swollen posteriorly, tapering for- 

 ward. Dorsal slit rather short, submedian, commencing forward of 



