126 H. A. Pilsbry — Littoral Mollusks from Patagonia. 



Art. XIII. — Littoral Mollusks from Cape Pairweather, 

 Patagonia ; by Henry A. Pilsbry. (With Plate I.) 



In the course of his paleontological explorations in Pata- 

 gonia in the interest of Princeton University, Mr. J. B. 

 Hatcher found time to make a small gathering of marine shells, 

 at the locality named above. The scarcity of information upon 

 the fauna of the east coast of South America makes it desir- 

 able to place the facts gained from even small collections on 

 record, to the end that the limits of the faunal provinces of 

 this coast may be more exactly defined, and their characteristics 

 more fully exposed. 



The fauna at the point in question is typically Magellanic, 

 with but little admixture of types from the Argentine fauna 

 of La Plata region. JVacella, Photinula and Trophon, Plaxi- 

 phora and littoral Prachiopoda, all occurring in a gathering so 

 small as this, at once indicate the western and not northern 

 origin of this mollusk population. Pullia alone is more 

 northern in distribution, this being its most southern outpost. 



The addition of the genus Sphenia to the Magellanic fauna 

 is interesting and unexpected. 



The figures on Plate I are three-fourths natural size. 



Muricid^e. 

 Trophon Gerversianus Pallus. 

 Trophon Gerversianus Phillipianus Dkr. 

 Trophon fasciculatus Hombron and Jacquinot. 

 Trophon textiliosus Hombr. and Jacq. PI. I, fig. 4. 



Shell fusiform, white or slightly buff tinted, with moderately 

 dilated body-whorl and short oblique or subvertical anterior 

 channel. Whorls about 6, convex, separated by a deep suture, 

 the last dilated toward the lip. Sculpture of numerous sub- 

 regular rounded spiral cords (28-34 on body- whorl, 8-11 on 

 penultimate whorl), separated by much narrower linear 

 grooves, and numerous vertical folds, which are rather closely 

 placed, separated by intervals narrower than themselves, are 

 somewhat arcuate in harmony with the lines of growth and 

 become obsolete upon the base. There are about 20 (18-21) 

 folds upon the penultimate whorl, pretty regular and equal; but 

 upon the latter part of the last whorl they become irregular or 

 in part obsolete. Aperture ample, over half the total length 

 of the shell, the outer lip somewhat expanding and faintly 

 crenulated ; columellar lip with a smooth white callous, reflexed 

 over and closing the axial chink ; siphonal fasciole well 

 developed. 



Alt. 36, diam. 23 mm.; alt. of aperture 22 mm. 

 " 39 « 21 " " " 21 " 



