CLASS GASTROPODA 
277 
central valve 1, anterior valve 13 slits. Length, ; breadth, 4 mm.; 
divergence, 100°. (Carpenter.) (Tryon and Pilsbry, Manual of Con - 
chology .) 
Type in ? Type locality, Catalina Island, California. 
Range. Catalina Island to Cerros Island, Lower California. 
Ischnochiton veredentiens Carpenter, 1864 
Supplementary Report, British Association for the Advancement of Science, 649. 
Tryon and Pilsbry, Manual of Conchology, 14:122. Proceedings of the California 
Academy of Sciences, 3:211. 
Margin similar. Small, arched, sculptured like Mertensii, but with two 
rows of bosses, one of which dentates the sutures. 10-20 fm. (Car¬ 
penter.) 
1.1. parva, albida, rosaceo tincta; valvis gothice arcuatis, jugo subacuto; 
tota superficie minute granulosa; areis lateralibus conspicue definitis, mi- 
noribus, costis diagonali et suturali validis instructis, bullis valde expressis 
munitis; valv. term, costulis subobsoletis radiantibus; areis centralibus 
elathris longitudinalibus utroque latere circ. viii. distantibus, expressis, 
subgranulosis, supra jugum obsoletis; interstitiis a costulis sub radiantibus 
decussatis; umbonibus conspicuis; marginibus umbonalibus a costis bulli- 
feris valde indentatis, dentibus viii.-x. jugum versus obsoletis, marginibus 
haud intortis; mucrone submediano, vix extante; marginibus lobatis ele- 
ganter a elathris pectinatis: intus, sinu maximo, planato, interdum serrato; 
laminis insertions acutis, late unifissatis, valv. term. circ. viii-fissatis, sub- 
grundis conspicuis; limbo pallii squamis majoribus, planatis, tenuibus, vix 
striatis. Long., 0.25; lat., 0.10; div., 90°. (Carpenter.) 
Shell small, whitish, tinged with roseate; valves gothic-arched, the 
jugum subacute; entire surface minutely granulose; lateral areas conspicu¬ 
ously defined, having strong diagonal and sutural ribs, provided with well- 
projecting, rounded grains ; end valves having subohsolete radiating riblets; 
central areas having about 8 distant, raised, subgranulose, longitudinal ribs 
on each side, the ribs obsolete at the jugum; interstices latticed with sub- 
radiating riblets; umbones conspicuous, the umbonal margin deeply toothed 
by a wart-bearing rib, the teeth 8 to 10, obsolete toward the jugum; margin 
scarcely intorted. Umbo of posterior valve submedian, slightly projecting; 
margin elegantly pectinated. Interior: sinus large, flat, valves having about 
8 slits; eaves conspicuous. Girdle having large flat, striated scales. Length, 
6}4 J breadth, 2mm.; divergence, 90°. (Carpenter.) (Tryon and Pilsbry, 
Manual of Conchology.) 
Type in ? Type locality, Catalina Island. 
Range. Point New Year to Catalina Island, California. 
[879] 
