196 
PATAGONIAN EXPEDITIONS : PALAEONTOLOGY. 
growth, and appearing distinctly crenulated, but not granulated. Be- 
tween the principal ribs are 1 to 3 fine striae, becoming more numerous 
with age. 
Measurements of largest fragment : Height, 58 mm; diameter, 14 mm. 
Remarks : Of the principal ribs, the uppermost is always the strongest, 
forming a distinct angulation. In most of the cases, the lowermost rib is 
the second in thickness, and the middle one is the finest. But in some 
cases the lowermost is finer than the middle one, and such individuals 
represent v. Ihering’s T. tricincta. In young individuals the suture is 
very shallow. 
Large individuals of this species are easily recognizable by the more 
elongated and more slender form, and by the thick revolving ribs. But 
young individuals and fragments, especially if a little worn, are almost 
indistinguishable from T. ambulacrum , since the slender form is not so 
evident. It is possible that some of the individuals recorded under T. 
ambulacrum belong really to this species. 
Record of specimens : Mouth of Santa Cruz River, 7 sp. ; Paso del Rio 
Santa Cruz, 1 sp.; Las Salinas, 3 sp. (one of them a cast); Mt. of Obser- 
vation, lower horizon, 2 sp. (one of them a typical T. tricincta). 
Distribution: Chiloe (Phil.); Santa Cruz (Phil., v. Ih. ) ; Jegua quemada 
(v. Ih.): Patagonian and Suprapatagonian beds (v. Ih.). 
Affinities: T perattenuata Heilprin (see: Dali, 1892, p. 316, pi. 16, f. 
5, 9), from the Pliocene of Florida has a general resemblance, but seems 
to be more slender. There are (according to Dali) Miocene species, which 
resemble T. perattenuata , especially T. terebriformis Dali (p. 31 1), but since 
there is no figure published, I cannot say what are the relations to T. 
breantiana. At any rate, we must take T. breantiana as a species of Neo- 
gene relations. 
126. Turritella patagonica Sowerby. 
PI. XXXI, Fig. 1 5 ®’ b . 
(?) 1846 T. pat. Sowerby, in: Darwin, Geol. Observ. South America, p. 
256, pi. 3, f. 48. 
1887 T. darwini Philippi, Tert. & Quart. Verst. Chiles, p. 75, pi. 9, 
f - 7 - 
1887 T. patagonica Philippi, ibid., p. 76 (after Sowerby). 
1889 T patag. Rochebrune & Mabille, in: Miss. Cap Horn, v. 6, p. 43. 
