PELTELLA. 231 



lineata. The specimen figured measures : convexity or oblique alt. 

 5.5, length 14.7, breadth 10.5 mill. The suture is hardly margined 

 and there are 2J whorls. It is from the type locality. 



Genus PELTELLA Webb & Van Beneden, 1836. 



Peltella W. & B., in Gu6rin's Mag. de Zool., cl. v, text for pi. 75 

 and 76 (1836). VON IHERING, Malak. Blatter (n. F.), viii, pp. 57- 

 81 (1886); also Archives de Mus. Nac. Rio de Janeiro, viii, pp. 135- 

 153. (Anatomy and systematic position.) 



Pectella GRAY, P. Z. S. 1847, p. 171. 



Slug-like, the foot spreading at the sides, weakly reticulated, with 

 some grooves running forward from the mantle, the tail without pore, 

 not keeled, sole scarcely tripartite; mantle region elevated or humped, 

 the mantle large, chiefly behind the middle, perforated in the middle 

 by a small oval slit ; the breathing pore in front of the middle ; anus 

 opening into a wide anal sack. 



Genitalia simple, opening below the right eye-tentacle. 



Retractor muscle system consisting of a very short columellar 

 muscle branching into three subequal bands, the median one buccal, 

 the right and left bands tentacular, and each with a group of foot 

 retractor muscles. 



Jaw horse-shoe shaped, thin, with many narrow converging plates. 

 Radula substantially as in the normal forms of Drymtzus. 



Shell mainly cuticular, Haliotiform, depressed, squarish-oval, with 

 about 1 J whorls, the spire small, flat and lateral ; open below, the 

 columella represented by a spiral lamina along the suture. 



Type Parmacella palliolum Fer. Brazil. 



Dr. H. von Ihering, who has given an excellent account of this 

 genus, correctly locates it in the Bidimulida. The sculpture of the 

 apical whorl is unknown. If spirally striated, the descent of the 

 genus from Simpulopsis would be indicated. 



P. PALLIOLUM (Ferussac). PI. 62, figs. 32, 33, 34, 35. 



Animal, preserved in alcohol (fig. 32), measuring 50 mill, long, 15 

 wide, 13 high. Foot broadly expanded laterally, rounded dorsally 

 behind the mantle, not keeled or regularly grooved ; no caudal mu- 

 cous pore. Sole only feebly tripartite. Genital opening below the 

 right eye-tentacle. Mantle rather large, 21 mill, long, 13 wide, 

 mainly on the posterior half of the body; a longitudinal slit 2 mill, 

 long in the middle, exposing the shell. 



