PLIOCENE AND PLEISTOCENE FOSSILS FROM ALASKA. 



29 



diameter at shoulder, 40 millimeters; height 

 of last whorl, 60 millimeters; of aperture, 40 

 millimeters. 



Station 627, 40 miles up Colville River 

 from the Arctic coast, with Pyrulofusus schra- 

 deri. Pliocene. Collected by F. C. Schrader, 

 1901. U. S. Nat. Mus. catalogue No. 210853. 



This species belongs to the general group 

 represented by O. lyrata Martyn but does not 

 agree closely with any of the known recent 

 forms. Other specimens have the ribs more or 

 less obsolete. 



Pyrulofusus schraderi Dall, n. sp. 



Plate V, figures 10, 13. 



Shell large, solid, dextral, with a short spire 

 and expanded last whorl; whorls about five, 

 rapidly increasing; nucleus large, swollen, of 

 about two whorls (decorticated in the speci- 

 men) ; subsequent whorls scidptured all over 

 with extremely fine, close-set spiral threads; 

 axial sculpture of inconspicuous incremen- 

 tal lines and on each whorl five very promi- 

 nent rounded sigmoid ribs diminishing toward 

 the base and stronger at the shoulder, below 

 which they are very obliquely inclined for- 

 ward; the interspaces are much wider than 

 the ribs ; the suture is deep but hardly chan- 

 neled; the whorl rises a little at the posterior 

 corner of the aperture and on the iimer lip 

 is a thin layer of enamel. The base and aper- 

 tme of the unique specimen are deficient. 

 Diameter of specimen at aperture from the 

 inner lip, about 50 millimeters; estimated 

 original length, about 75 millimeters. 



PHocene at station 627, 40 miles up Col- 

 ville River from its mouth at the Arctic coast, 

 in silt beds 80 feet above the river, 5 to 15 

 feet below the base of loess, 20 feet below the 

 siu^ace of the soil. Collected by F. C. Schra- 

 der. U. S. Nat. Mus. catalogue No. 210854. 



Thais (Nucella) nomeana-DaU, n. sp. 



Plate V, figure 9. 



This form is represented only by worn 

 and more or less defective specimens which 

 resemble the form from the Pliocene of Coos 

 Bay, Oreg., described by the writer. 



It is certainly a precursor of N. lamellosa 

 Gmelin and would probably by casual ob- 

 servers be referred to as a variety of that 

 species. The shell is nearly smooth, only ob- 



solete traces of spiral sculpture being apparent. 

 The general aspect is rude, the suture closely 

 appressed. None of the specimens show any 

 denticulation on the inside of the outer lip; 

 there is a strong siphonal fasciole and a very 

 narrow chink between the fasciole and the 

 pillar, which is thick and callous, though 

 there are no indications of a thickening of the 

 inner lip. In size and general characteristics 

 this form closely approaches N. lamellosa. 



Station 5074, Pliocene on Center Creek, about 

 1^ miles north of Nome, from the second 

 beach. Collected by E. M. Kindle. U. S. 

 Nat. Mus. catalogue No. 324318. 



Littorina palliata Say. 



Shell small, smooth, solid, turbinate, of 

 about four rounded whorls; suture distinct, 

 appressed ; surface with hardly visible in- 

 cremental lines; the rotimdity of the whorls 

 slightly compressed in front of the suture; 

 aperture roimded, slightly angulate at the 

 posterior commissure; outer lip thick, not re- 

 flected, entire; body and umbilical region 

 with a thin flattened layer of caUus which 

 merges evenly into the basal lip; base con- 

 vexly rounded. Pleight, 12 millimeters; diam- 

 eter, 12.5 millimeters; last whorl, 10 milli- 

 meters in height. 



Station 5078 (226). PHocene. From pros- 

 pector's pits on the second beach, one-half 

 to one-fourth mile east of Nome. Collected by 

 E. M. Kindle and R. D. Mesler, 1908. U. S. 

 Nat. Mus. catalogue No. 324319. 



This species is of the type of Littorina pal- 

 liata Say, of which no living form now in- 

 habits the Pacific Ocean or any part of the 

 Arctic coast west of Mackenzie River and 

 east of the Lena. The specimen retains some 

 of the yellowish coloration characteristic of 

 the Atlantic form, and after a scrutinizing 

 comparison with specimens of Littorina pal- 

 liata from Rhode Island and with all the 

 varieties of ohtusata from Europe, no characters 

 have been discovered by which the Nome fos- 

 sil can be distinguished from Littorina pal- 

 liata. This is natural enough, as obtusata- 

 has never been found in America, whereas pal- 

 liata is excessively common on the New Eng- 

 land coast in locaUties where it has not been 

 supplanted by the introduced Littorina litorea,. 



