Art. IX.] Herrick-Johnson, G 60 logy of the Albuquefque Sheet. 235 
DESCRIPTION OF PLATES. 
PLATE XXVII. 
Figs. 1-2. Buchiceras swallovi, Shumard. Dorsal and lateral views ol 
gibbous form. 
Figs. j-^. Buchiceras swallovi, var. puercoensis, var. n. Dorsal and ven- 
tral views. Both forms occur in septaria concretions of the Colorado formation 
in the Rio Puerco valley. 
PLATE XXVIII. 
Fig. /. Prionocyclus woolgari, Mantell. Sandstones north-east of San 
Francisco in Rio Puerco valley. Tres Hermanos sandstone above gasteropod 
zone. 
Figs. 2-g. Placenticeras costatus, sp. n. From septaria concretions near 
Punta de la Mesa, Rio Puerco valley. 
Fig. /j.. Harpa ? loccidentalis, sp. n. East of Sandia mountains. 
Fig. 5. Undetermined gasteropod. 
Fig. 6. Turritella whitei, Stanton. 
PLATE XXIX. 
Fig. I. Rostellites ambigua, Stanton. 
Fig. 2. Volutomorpha (?) nova-mexicana, sp. n. Una de Gato. 
Figs, j and Rostellites dalli, Stanton. Fox Hills group. 
Fig. /f.. Vanikorpsis tuomeyana M. and H. Fox Hills. 
Fig. 6. 
Figs, y, a and 6. Gyrodes depressa, Meek. Fox Hills strata. 
Fig. 8. Ostrea franklini, Coquand ? 
Fig. g. Cf. Ostrea translucida, M. and H. See Plate XXIV, Figs. 7-10. 
Gasteropod zone below Tres Hermanos sandstone. 
PLATE XXX. 
Fig. I. Inoceramus fragilis, H. and M. 
Fig. 2. Inoceramus sp. Caballo mountains. 
Fig. j>. Gryphaea vesicularis, Lam. 
Fig. Inoceramus fragilis? binge view. Fox Hills. 
Fig. 5. Mactra pulchella, sp. n. 
Figs. 6 and 7. Caryates veta, Whitfield. Septaria concretions. 
Fig. 8. Ostrea sp. 
PLATE XXXI. 
Fig. I. Pinna petrina. White. Septaria concretions. 
Fig. 2. “ 
J. “ . 
Fig. 4. “ 
All the figures are one half natural size. 
