C. Interspaces with silky, wavy crinkles; 3 mm.; Coronado Islands | | cleo Bartsch |
|
- Interspaces smooth, 3 mm.; Catalina Islands, south
| | californica Bartsch |
|
D. Whorls decidedly inflated; 3 mm.; Monterey south | | bakeri Bartsch |
|
|
E. With very fine, numerous axial threads (48 to 55 on last whorl) | | F |
|
- With coarse riblets (36 on last whorl; 14 on next to last); 3 mm. Alaska to Monterey
| | newcombei Dall |
|
F. Shell slender; 2 mm.; San Pedro south | | dalli Bartsch |
|
- Shell not as slender; 3.5 mm.; Redondo Beach south
| | coronadoensis Bartsch |
|
|
Key to the Atlantic Coast Rissoina
A. Shell sculptured with riblets or spiral lines | | B |
|
- Shell smooth, glossy-white; 4 mm.; Carolinas, Florida, and West Indies; syn.: laevigata C. B. Ads.
| | browniana Orbigny |
|
B. With axial ribs more prominent than spiral threads | | C |
|
- With axial ribs not more prominent than spiral threads
| | F |
|
|
- Axial ribs and spiral threads both present
| | E |
|
D. 4.5 to 6.0 mm.; white or stained yellow; 16 to 22 ribs; South Florida and the West Indies | | bryerea Montagu |
|
- 3.0 to 5.0 mm.; white; 11 to 14 ribs; suture sometimes deep; North Carolina to Florida and the West Indies
| | chesneli Michaud (Pl. 22u) |
|
E. 4 to 5 mm.; ribs strong but disappearing on base; spiral threads strongest on base; white to rusty; southeast Florida and the West Indies | | multicostata C. B. Adams |
|
- 6 to 7 mm.; 25 to 28 low, weak ribs, spirally striated or pitted between; glossy; white to yellowish; North Carolina to the West Indies
| | decussata Montagu |
|
F. Sculpture strongly cancellate | | G |
|
- Not strongly cancellate; low, spiral threads dominant; axial ribs faint; weakly cancellate; 5 to 10 mm.; southeast Florida and the West Indies
| | striosa C. B. Adams |
|
G. 5 to 7 mm.; white; strongly cancellate; depressed interspaces large and square; southeast Florida and the West Indies | | cancellata Philippi |
|
|
