CLASS GASTROPODA 
307 
libus et valvis ultimis tenuissime granulosis, granulis longis, irregulariter 
radiantibus; areis centralibus iisdem lineis longitudinalibus undatis in- 
structis; marginibus valvarum subquadratis, suturis parvis; jugo acuto, 
mucrone inconspicuo; limbo angusto, sublaevi, tenui; intus virescente, 
valvarum marginibus et jugo impresso albidis; valvarum marginibus vix 
arcuatis, sinu parvo, inciso. Long., .9; lat., .5 ; alt., .2 poll. (Carpenter.) 
Shell rather small, strongly elevated, the dorsal ridge acute; valves 
thin; sculpture minute and delicate, varying between a minute granulation 
and a fine pitting; the sutures delicately denticulate; diagonal riblets obso¬ 
lete or delicately raised. Color olivaceous obscurely mottled with dusky, 
the tail valve having a light ray behind. Interior blue-green. Tail valve 
slightly waved upward in the middle behind, and having either a simple 
narrow caudal slit, or a slit with a small tooth set in its apex. Lateral 
slits of the tail valve generally double on one side. Girdle narrow, sparsely 
hairy. Length, 22j4; breadth, 12>^ mm.; divergence, 105°. (Carpenter’s 
type.) (Tryon and Pilsbry, Manual of Conchology.) 
Type in Academy of Natural Sciences, Philadelphia, No. 35729. Type 
locality, Santa Barbara, California. 
Range. Santa Barbara to San Diego, California. 
Mopalia cirrata Berry, 1919 
Lorquinia, January 1919, 5. 
Shell of moderate size, oval, with slightly arcuate side-slopes. Head 
valve with eight strong, somewhat tuberculose radial ribs and weaker 
sutural ribs, the interstices checkered by pits and squarish grains like 
basket work. Median valves with strong diagonal ribs; sutural ribs more 
or less obsolete; the areas between with even, basket-like sculpture; central 
areas on each side with some twenty arcuate, granulose riblets, strongly 
converging toward the jugum, and conspicuously latticed by a somewhat 
weaker system of curved transverse riblets; a narrow tract along the 
jugum smooth. Tail-valve small, with a slightly elevated mucro and nar¬ 
row, abrupt, caudal sinus. Color of shell a soiled buff with brown suffusion 
and mottling. Girdle moderately wide, minutely scaled above, and bearing 
an inner sutural series of extremely long, slender setae, furnished with 
slender branching aciculae; series'of minor setae near the margin. (Berry.) 
Type in Berry Collection. Type locality, “Albatross” Station 4263, Dun- 
das Bay, Alaska. 
Range. Known only from type locality. 
[ 909 ] 
