2l8 PATAGONIAN EXPEDITIONS I PALEONTOLOGY. 



1463. TROPHON LACINIATUS VAR. INORATUS (Pilsbry). 



PI. XXXIV, Fig. 8". 



1897 ? varians v. Ihering, in: Rev. Mus. Paul., v. 2, p. 296. 

 1897 ^ inornattis Pilsbry, in: Pr. Acad. Philad., p. 330, textfig. 



This form, found at Cape Fairweather associated with the typical 

 form of T. laciniattis, is hardly anything more than a variety of the latter. 

 Its external form is more or less slender, sometimes quite swollen. Sur- 

 face without lamellose varices, or only with slight traces of them, smooth 

 except for lines of growth. 



Height, 60 mm, diameter, 37 mm. 



Remarks: We possess individuals that show slightly developed vari- 

 ces, in some parts of the shell, which fact makes it the more certain that 

 it is only a variety of T. laciniatus. The upper part of the whorls has 

 sometimes a distinct angulation and a distinct, but narrow, flattened 

 space near the suture (var. gradata v. Ih.) ; in other cases no trace of 

 this angulation is seen, the whorls being evenly convex. 



This variety much resembles some of the varieties generally classed 

 with T. geversianus, especially : T. geversianus var. calva ( Kuester & 

 Kobelt, 1878, p. 305, pi. 75, f. i, and Tryon, 1880, pi. 32, f. 338), and T. 

 geversianus var. varians (Tryon, pi. 32, f. 346). Some of our specimens, 

 for instance, that figured by Pilsbry, which are more obese- and have no 

 angulation, are indistinguishable from T. varians as figured by Tryon. 

 On the other hand, we have specimens that are more elongate, and the 

 complete lack of spiral sculptures, as well as the fact that this form is 

 found associated with T. laciniatus, is in favor of the course adopted, to 

 leave it with T. laciniatus. 



The fact that T. laciniattis offers the same variations as T. geversianus 

 is very interesting, and would bring these two supposed species still 

 closer together. 



Record of specimens: Cape Fairweather, n sp.; San Julian, Darwin 

 Station, above Patagonian beds, 3 sp. 



Distribution: T. varians, mentioned by v. Ihering from Santa Rosa (or 

 Punta Raza, see pp. 112, 119 and 177), between Santa Cruz and San 

 Julian, and from between San Jorge and Deseado, from the Tehuelche 

 beds, is no doubt this form. 



