PALEONTOLOGY ZORRITOS FORMATION 51 



have had representatives in the early Miocene which may be 

 taken to be the ancestors of the living distortd. Triumphis 

 is certainly very closely related to Gabb's genus Agasoma ; 44 

 Fischer 45 notes that the two are probably synonymous, and 

 a close study of the Californian Agasomas may show this to 

 be the case. It is highly probable that a closer relationship 

 than that now expressed between Triumphis and Agasoma 

 exists, and it is the opinion of the writer that they are not 

 farther apart, actually, than subgenera under the same gen- 

 eric heading. 



Lower Zorritos. Between Quebradas Heath and Charan. 



Family MURICIDAE 



Genus MUREX Linnaeus 



Murex laqueoratus n. sp. 



PLATE II Fig. 4. 



Shell small, turreted, fairly stout. Whorls about six in 

 number, the first two smooth, the remainder delicately sculp- 

 tured and convex. Sculpture of regular longitudinal folds, 

 eight to the whorl, which are negligible at the suture, in- 

 creasing rapidly to full strength at the mid-line of the whorl, 

 and decreasing again. On the body whorl all except the last 

 two continue over the base as narrow rounded folds; the 

 last two die out just below the shoulder. Spiral sculpture of 

 fine threads, about six to the whorl, with occasional inter- 

 stitial threads above or below the periphery of the whorls; 

 there the two central threads are prominent, forming a band 

 which heightens the prominence of the nodes on the longi- 

 tudinal ridges. On the body whorl there are twelve pri- 

 mary threads between the band and the base, with occasional 

 interstitial threads. Aperture almost circular, smooth within, 



"Geol. Surv. Cal. Palaeont., vol. 2, p. 46, 1869. 

 45 Man. de. Conch., p. 627, 1887. 



