Phyllomyza Fallen, 1810 (Milichiidae: Phyllomyzinae) is characterized by the following features: 3 lateroclinate orbital setae; occiput not strongly concave in top view; palpus and 1st flagellomere in male usually greatly enlarged, longer than broad; lunule
usually with a pair of setae (Brake 2000).
4 x of total head width; frontal vitta markedly narrowing downwards: on upper part more than V of frontal width, above lunule
much narrower than parafrontalia.
Shell with strongly sloping dorsoposterior margin meeting short posterior margin with an obtuse angle; anterior margin convex; ventral margin flatly convex; valves angulated from umbonal area to ventroposterior margin; area dorsal to angulation concave; beaks tightly incurved near anterior margin, prosogyrate; lunule
and escutcheon not deeply impressed; comarginal ridges become coarser during growth with equal-sized interspaces, eight in 2 mm near ventral margin; internal features not observed.
The pale half-moon shape at the base of each nail is called the lunule
, which shows where the hardening process is not yet complete.
in the southern quahog is at least as wide as high in the southern quahog, but is narrower in the northern quahog.
The genus Neophyllomyza Melander, 1913 (Milichiidae: Phyllomyzinae) can be separated from other genera of the subfamily Phyllomyzinae by the following characteristics: paired cruciate setae present along the middle of the front; fron-to-orbital setae extending quite to antennae, the upper ones diverging, the lower converging; face excavated, cheeks narrow, oral vibrissae large; proboscis long, slender, geniculate; lunule
small, bare; one humeral, 2 notopleural, one presutural, 2 supra-alar; one katepisternal, no anepisternal setae (Melander 1913; Brochu & Wheeler 2009).
General colouration: Scutum shiny brown, abdomen shiny yellow, with translucent tergites 1+2-4, tergite 5 brown, with grey pollinosity; fronto-orbital plate and parafacial brown, silver pollinose from certain angles; lunule
reddish brown; antenna, arista and palpus dark brown; anterior spiracle brown; calypters whitish; haltere with yellow knob.
scabrosa of white apical lunule
markings with small medial white marks and heavily punctured elytra, flattened white hairs on the underside of the abdomen and numerous conspicuous white hairs on sides of the pronotum (Fig.
For head ratios: the head length and height were measured in lateral view, respectively, from the tip of the frons through the posterior occiput, and from the ocelli through the bottom edge of the subgena; the head width, frons width, and frons length were measured in dorsal view, with head width measured through the widest part, frons width through the anterior ocellus and a second measurement through the top of the lunule
, and frons length from the anterior ocellus to the anterior edge of the frons.