220 
PATAGONIAN EXPEDITIONS I PALAEONTOLOGY. 
they are crossed by numerous longitudinal, sometimes variciform, ribs. 
Mouth ovate, elongated into an open, slightly curved canal of medium 
length, a little shorter than the mouth. Outer lip thickened and crenu- 
lated on inner side. 
Height, io mm, diameter, 4.5 mm; a larger, but incomplete, individual 
has a diameter of 6.5 mm; Cossmann gives: height, 13 mm, diameter, 
6 mm. 
Remarks : This species differs from T. leucostomoides in the more 
numerous (30 and more), and finer longitudinal ribs, and further, in the 
more slender form. 
Record of specimens: Mouth of Santa Cruz River, 14 sp. 
Distribution: Jegua quemada, Suprapatagonian beds (Costa.). 
149. Urosalpinx pyriformis (v. Ihering). 
PI. XXXIV, Fig. 11. 
1897 Trophon p. v. Ihering, in: Rev. Mus. Paul., v. 2, p. 295, pi. 3, f. 5. 
Shell ovato-pyriform, spire short. Whorls with spiral ribs, 2-3 of 
which are stronger, the uppermost of them forming an angulation on the 
whorls. Varices lamellar, 7-9. Mouth ovate, canal short, straight. 
Height, 14 mm; diameter, 9.5 mm. 
Remarks: Our specimen is smaller than that figured by v. Ihering, and 
poorly preserved, v. Ihering’ s figure is very indistinct, and shows only 
the external form, which agrees completely with our individual, v. Iher- 
ing mentions 3 stronger spiral ribs, which are not seen in his figure. 
Our individual has only 2 stronger ribs ; and further, he gives 9 varices, 
while I see only 7. 
There is a very striking resemblance to Murex hatcheri: the chief dif- 
ference is, that M. hatcheri has only 5 or 6 varices, which are distinctly 
lobate. In our individuals of M. hatcheri , the varices on the upper whorls 
are so much obscured, that it is impossible to count them correctly, but 
they seem to be more numerous there. Possibly, T. pyriformis is only 
the young stage of M. hatcheri , but the lack of more material prevents 
me from determining this question. 
Record of specimens : Lake Pueyrredon, base of Tertiary, 1 sp. 
Distribution : Jegua quemada, Suprapatagonian beds (v. Ih.). 
