Head blackish brown with grayish microtomentum; orbital plates subglossy blackish brown with microtomentum; ocellar triangle darkish brown without microtomentum; lunule
strap-shaped, darkish gray with black margin.
pyramidatoides, the lunule
is quite small or nearly obsolete and the posterior region is straight and has a very pronounced ridge, while P.
Shell elongate, equivalved, dorsal and ventral margins subparallel; beaks rise above dorsal margin, tightly incurved, prosogyrate; posterior margin more broadly curved than anterior margin; greatest length below midheight, greatest width anterior of midlength; lunule
and escutcheon present; valve surface with numerous broad, comarginal, rounded plicae commonly becoming coarser ventrally; some plicae bifurcate posteriorly; muscle scars and hinge not observed.
of the host may serve the female ophiuroid as a convenient site for attachment, or the concave shape of the lunule
may provide protection from abrasion by the sand.
Orbital plate subshiny black with microtomentum; ocellar triangle brownish without microtomentum; lunule
small, yellow with brown margin.
idubedae has a well developed lunule
and the cardinal tooth in the right valve, which is much thicker than in M.
Diagnosis: Frontal triangle reaching lunule
; palpus yellow; dorsocentral setae 1+3; crossvein dm-cu straight; femora brownish grey, tibiae yellow; fore tibia with posteroventral seta; mid tibia with 1 posterodorsal seta; hind tibia with 1 or 2 anteroventral setae; abdomen with dark brown lateral maculae, strongly grey-pollinose on median vitta and laterally, around the maculae.
Diagnosis: The following combination of features will aid recognition of this genus: body elongate, tapering posteriorly; lunule
low, bare; 2 pairs of strong reclinate fronto-orbital setae present; postocellar setae present, convergent; ocellar setae strong, proclinate; 2 postsutural dorsocentral setae present, lacking presutural dorsocentral seta; frons lacking black transverse band across anterior fronto-orbital setae; anepisternal seta absent.
Frons shining dark yellow, without brown areas, 1.7 x as long as wide in its narrowest part; with 1 short proclinate orbital seta and 12-16 irregular setulae at each side 1-1.5 x as long as orbital seta, forming 3 irregular transverse rows posterior of lunule
. Parafacial and subocular sclerite entirely shining yellow, without brown areas.
1 brown, silver-grey pruinose, yellow-brown basally, moderately short, ca twice as long as wide, apex squarely rounded, arista with 11 or 12 long dorsal branches and 3 or 4 ventral branches in addition to terminal fork; lunule
and face uniform silver pruinose throughout, face with extremely broad silver fascia (adjacent to eye margin), not contrasting markedly with face, facial carina developed as a prominent ridge; 1 pair of moderately weak vibrissae; occiput with strong, black postocular setae; gena wide, eye height/genal height ratio: 1: 10 (HT), silver pruinose, abruptly dirty brown beyond basal angle; palpus narrow, yellow-brown, black microtrichose.
Few of us remember the Lunule
Manicure, first popular in the Forties.