TONICIA. 203 



9; teeth finely crenulated outside and at edge, rather thin, and 

 colored red. As in other species having a posterior mucro, the tail- 

 valve teeth are directed forward. 



Girdle yellowish, leathery, nude and smooth. 



Length 28, breadth 15 mill. ; divergence 108. 



Callao ; and Chili (U. S. E. E.) 



This species differs from all of the T. elegans group in lacking 

 sculpture upon the central areas and engraved grooves along the 

 dorsal ridge; and from other species of Tonicia in the red sutural- 

 plates, teeth, etc. The blunt mucro is posterior, and the teeth in the 

 tail-valve are directed forward. The posterior margin of the tail 

 valve is broadly waved upward in the middle, as in Eudoxochiton. 



T. HORNIANA Rochebrune. PI. 43, figs. 50, 51. 



Shell ovate-elliptical, carinated, rufous, marbled with buff and 

 roseate ; anterior valve radially costate, posterior valve small ; inter- 

 mediate valves having the central areas minutely concentrically 

 striated ; lateral areas multi-sulcate and ornamented with two lines 

 of dots. Marginal ligament dull roseate. 



Length 19, breadth 14 mill. (Rochebr.} 



Orange Bay, Patagonia. 



T. homiana ROCHEBR., Polyplac. Cap Horn, p. 139, t. 9. f. 7. 

 T. MARTIELI Rochebrune. PI. 43, figs. 48, 49. 



Shell ovate-elongate, strongly carinated, the ends of the valves 

 curved backward, brown-rose, anterior valve radially strongly 

 costate; posterior valve small; intermediate valves having the 

 central areas transversely lineated, lines denticulate; lateral areas 

 granulated and margined by a squamate band. Marginal ligament 

 violaceous-rufescent. Length 21, breadth 14 mill. 



Straits of Magellan. 



T. martieli ROCHEBR., Polyplac. Cap Horn, p. 139, t. 9, f. 8 

 (1889.) 



T. LEBRUNI Rochebrune. PI. 43, figs. 52, 53. 



Shell ovate-elliptical, carinated, shining, violaceous or greenish- 

 roseate. End valves radially most minutely striated ; intermediate 

 valves having the lateral areas covered with tubercles ; the central 

 areas concentrically sulcate, the sulci wavy ; marginal ligament 

 narrow, leathery, whitish-violaceous. 



Length 29, breadth 12 mill. (Rochebr.') 



Punta Arena*, Orange Bay, St. of Magellan. 



