Macoma constricta (Bruguiere, 1792) - Constricted Macoma

Measuring up to 7.5 cm long, the Macoma constricta is thin, but fairly strong, as well as fairly inflated. It is white or grey in color with a thin, fawnish-grey periostracum. The interior of the shell is smooth and the same color as the rest of the shell. It is pointed and partially truncate posteriorly. There is a kink or indentation in the posterior ventral margin, which in most specimens can be traced radially across the surface to the beaks. This kink is bordered by two ridges or folds, which may also be traced radially to the beaks. Surface sculptured by numerous growth lines and extremely fine radial rays, but is nevertheless still fairly smooth. There are two cardinal teeth in each valve. Lateral teeth are absent (as in all species of Macoma). Pallial sinus very well developed reaching almost to the anterior muscle scar and is confluent along most of its length with the pallial line. The anterior adductor muscle scar is slightly thinner and longer than the posterior one (cf. Strigilla gabbi). Some specimens may be deformed; we found a single right valve where the posterior end was very short.