1905.] NATURAL SCIENCES OF PHILADELPHIA. 237 
Miss Mary Cooper collected specimens in Manzanares Valley, near 
Rowe, New Mexico, which have been reported on by Prof. Cockerell 
and Miss Cooper (Nautilus, XV, p. 109). They are in all respects like 
‘those of the type locality except that the inner basal denticle is more 
obsolete, as in fig. 39. The curve of diameters is the same as in the 
Beulah lot. The specimens I have seen are from 15 to 16 mm. diam. 
A single specimen I have seen from Cooper’s Mill, near Rowe, New 
Mexico, measures 8.7 x 16 mm., with 5? whorls. The inner basal den- 
ticle is low, as in Manzanares shells. 
The shells from Pecos, New Mexico (Pl. XIII, figs. 48-45, collected 
by Cockerell), are intermediate between thomsoniana and portere; the 
size being that of the former, while in 14 out of 17 specimens before 
me the basal tooth is double, as in portere. In the others it is simple, 
as in thomsoniana. ‘The umbilicus is rather wide, as in portere. Prof. 
Cockerell refers the form to A. t. coopere. Its location depends upon 
whether size is more important than the teeth as an index of 
affinity; but the question of name is of minor importance in view of 
the intergradation of the whole series. Specimens measure: . 
Alt. aan RD ASA Bin 8 8 731 TRO 
Diam. Lar Ay TAG CAG 148) DS. Leds nae 
Whorls re OMA NOSeS wI5E StS ase 
Alt ANRC Tonle a ee a eR gO 
Diam. OW ARIE on IS IS By ABO ae 
Whorls Sul) a oe FM NG Facet 5 ees Sea a 2 it 6 
There is practically no variation in number of whorls, or in the pro- 
portion of altitude to diameter. The variation in diameter is not great, 
but serves to connect thomsoniana and portere, but the skew of the 
curve is toward the larger size of portere. 
Ashmunella thomsoniana pecosensis Ckll. Pl. XIII, fig. 38. 
Cockerell, Nautilus, XVI, p. 105, January, 1903. 
Shell like thomsoniana in shape, size, the small umbilicus and the 
simple basal tooth; but differing in sculpture, a coarse, low costation 
being superposed upon minute growth-lines and microscopic spirals 
similar to those of A. thomsoniana. Aperture as in thomsoniana, the 
“lip and teeth strongly developed, the basal tooth single.” 
Alt. about 6.3, diam. 11.8 mm. 
Vallé ranch, Pecos, New Mexico. A Pleistocene fossil. Type No. 
84,209, A. N.S. P., collected by T. D. A. Cockerell. 
