XII LIST OF ILLUSTRATIONS. 
Page. 
6. Plastron of Kinosternon arizonense. No. 10462, U.S.N.M. Paratype. is 
Female. «ab, abdominal scute; an, anal scute; epi, epiplastral bone; hyo, 
hyoplastral bone; hypo, hypoplastral bone; ziph, xiphiplastral bone. 
Mote than: one-halt tiatural S120. Jo ene oc en 08 nee ee oe eee 6 
7. Plastron of Kinosternon arizonense. No. 10462, U.S.N.M. Paratype, 
female. Superior view, epi, epiplastral bone; hyo, hyoplastral bone; 
hypo, hypoplastral bone; 5th per, 6th per, peripheral bones 5 and 6; ziph, 
xiphiplastral. “One-half natural Sizer oe ee cee ee vi 
MINERALOGIC NOTES ON PUCHERITE, PYRITE, TRICHALCITE, AND WAVELLITE. 
By Earl V. Shannon. 
1-5. Pyrite crystals irom: Stillwater, Arkansag- 1 -- ooo obs ee ee ee 2 
6. Orthographic and clinographic drawings of a pucherite crystal from 
Mings (Geraes; Brazile eae ea nee tee ead 4 oa aw aw as Ne en wee ae a 
7-8. 7. Optical and crystallographic structure of twinned crystal of trichal- 
cite. 8. Orthographic and clinographic drawings of simple tabular 
Crystalloitrichaclates.. See ees Fa eee Sis en eo oe Does es 5 
9-10. Orthographic and clinographic drawings of wavellite crystals from Arkan- 
BAe ates cite cc oe c Sis wale em Slaletate are cle tal ac ame ew aictalale che ela ee a Seen 7 
A SPECIES OF ROUND WORM (GONGYLONEMA) FROM DOMESTIC SWINE IN THE 
UNITED STATES. 
By Edward A. Chapin. 
1. Gongylonema ransomi. Anterior extremity of female..............-------- 1 
2. Gongylonema ransomi. Caudal extremity of male...............-...-....-- 2 
3. Gongylonema ransomi. Spicules and gorgeret of male.........-.........-- 2 
ON SIDERITE AND ASSOCIATED MINERALS FROM THE COLUMBIA RIVER BASALT AT 
SPOKANE, WASHINGTON. 
By Earl V. Shannon. 
1. Showing approximate extent of Columbia River basalt area. .......-.-.-. 2 
2-3. Common habits of plagioclase crystals from basalt. ..........-----.---- 6 
4-5. Magnetite from basalt cavities. 4, Common octahedral form showing 
depressed faces. 5, Showing a number of octahedrons aligned in parallel 
yer. 1 10) ¢ SRP fae Ne Sgn Oe Rr RRR Gs Ps aiia RS Riel ROD ely Rhy we els if 
6-8. Cristobalite crystals from basalt. 6, Simple cuboctahedron showing 
forms a(100) and 0(111). 7, Sketch of imperfect cuboctahedral crystal. 
8, Cuboctahedron with edges beveled by trapezohedron N (211)...-.-..- 9 
9-12. Siderite from Spokane. 9. Radiate form of first generation siderite. 
10, Common ‘‘trigonal hour-glass” form of first generation siderite. 
11, Curved crystal of second generation siderite. 12, Crystal draw- 
ings in orthographic and clinographic projections of crystal of siderite. 11 
13. Barite crystal from basalt. Simple crystal showing tapering..........-.-- 17 
14. Barite crystal showing 13 forms. - From basalt... . 2.52 2.1 sot s2cele beseck 17 
THe DERMANYSSID MITES OF NorTH AMERICA. 
By H. E. Ewing. 
1. Entonyssus halli, new species. Ventro-internal view of chelicera........-.-- 5 
2. Ixodorhynchus liponyssoides, new species. Side view of chelicera.......-..- 5 
3. Ixodorhynchus liponyssoides, new species. Ventrolateral view of maxillae... 6 
