Figure 1 in Morphological perspective on the classification and evolution of Recent Pterioidea (Mollusca: Bivalvia)

Figure 1. Diversity of shell morphology in the Pterioidea. Major features of the shell, showing the exterior of the right valve and the interior of the left valve [frontal view is shown in (G)]. The shells are arranged with the hinge axis orientated horizontally and anterior to the right. A, Isognomon alatus (AMNH 100419, 46.9 mm); B, Pinctada mazatlanica (AMNH 311788, 58.6 mm); C, Crenatula modiolaris (AMNH 27950, 49.0 mm); D, Pteria sterna (AMNH 311789, 58.0 mm); E, Electroma alacorvi (USNM 675754, 48.1 mm); F, Pulvinites exempla (AMS C.129659, 62.6 mm); G, Malleus anatinus (MNHN Expédition Montrouzier September 1993, Stn 1261, 44.38 mm height); H, Malleus (Malvufundus) candeanus (MCZ 340681, 69.9 mm height); I, Vulsella vulsella (AMNH 27884, 84.2 mm). For clarity, specific structures are labelled only on a single image where best observed. Abbreviations: aa, anterior auricle; ams, posterior adductor muscle scar; bn, byssal notch; br, byssal ridge; ccs, commarginal calcitic scales; cl, calcitic lamellae; cps, commarginal periostracal scales; fo, foramen; hl, hinge line; lg, ligament; mlg, multivincular ligament; nb, border of nacreous layer; pa, posterior auricle; pmg, prismatic margin; pms, pallial muscle scar; pr, pallial ridge; prms, posterior (pedo-byssal) retractor muscle scar; rs, radial stripes; u, umbo; um, undulating shell margins; vr, visceral rim.