PANAMIC-PACIFIC PELECYPODA 151 



3. Primary spines much enlarged, often flattened or fluted between wide, 

 open interspaces (one secondary and two tertiary generally). Valves 

 rounded and symmetrical in shape, convex. Color uniform. 



S. princeps unicolor 



B. Shell always much distorted, the valves strongly unsymmetrical, the 

 attachment scar covering a large part of the surface of the lower valve 

 and bordered by a profuse development of foliated concentrics. 



4. Spiny ribbing strongest on the posterior slope of the upper valve. 

 Cardinal area and beak generally turned backwards. Color orange 

 to wine-red. 



S. calcifer 



Spondylns princens Broderip Plate 22. figures 4. 5, 6, 8; 



Plate 86, figures 1. la, 4 



Spondylus princeps Broderip, 1833, Proc. Zool. Soc. London, pt. 2, p. 4. (ad Insulara 

 Platam, Columbiae Occidentalis). — Reeve, 1856, Conch. Icon., vol. 6, Spondylus, 

 pi. 2, fig. 9. — Hertlein and Strong, 1946, Zoologica, vol. 31, pt. 2, No. 5, pp. 

 62, 63. 



Spondylus dubtus Broderip, 1833, op. cit., pt. 2, p. 4, 



Spondylus leucacantha Broderip, 1833, Proc. Zool. Soc. London, pt. 2, p. S. (ad Insulam 

 Platam).— Sowerby, 1848, Thes. Conch., vol. 1, p. 423, No. 14, pi. 87, figs. 35, 

 36. — Reeve, 1858, Conch. Icon., vol. 6, Spondylus, pi. 2, fig. 6. 



spondylus unicolor Sowerby, 1847, Proc. Zool. Soc. London, p. 86. — Sowerby, 1848, Thes. 

 Conch., vol. 1, Spondylus, pp. 423, 424, pi. 85, fig. 19. 



spondylus pictorum Sowerby, 1848, Thes. Conch., vol. 1, Spondylus, p. 422, No. 13, 

 pi. 86, fig. 28; pi. 86, fig. 45.— Reeve, 1856, Conch. Icon., vol. 6, Spondylus, 

 pi. 6, fig. 24 Isla la Plata. Probably not of Chemnitz, 1784. 



Spondylus crassisquama of some authors but not of Lamarck, 1819. 



Shell of medium or large size, rounded, subcircular, pectiniform, sub- 

 equivalve, attached by the umbone of the lower valve, the attachment scar 

 small or of medium size. Sculpture of the upper valve of widely spaced or 

 closely crowded spines arranged in radial rows of primary, secondary, and 

 tertiary strength, the primary spines often much enlarged, elongate spike- 

 like or flattened or fluted, sometimes divided at the ends. The primary 

 spines are set in six rows; the space between each pair carries a secondary 

 row of spines, in turn bordered on each side by one or two rows of much 

 smaller tertiary spines; if the space between the spines is wide and open, its 

 surface is marked with a minute sculpture like that of the weave of coarse 

 linen. Cardinal area of the lower valve, high, triangular, its tip usually 

 straight. External color varies from white through orange to wine and coral- 

 red, the spines similar or with lighter tints. Interior white, porcellaneous, the 

 ventral margin bordered by a wide, colored band, usually reddish purple. 



As noted by Hertlein and Strong, there is some uncertainty as to the 

 earliest name which should be used for this species. In some collections, the 

 species is often labelled S. crassisquama but as pointed out by Favre in his 

 work illustrating the Lamarckian types of fossil pelecypoda, the original 

 specimen of crassisquama is a fossil shell from Cartagena, Colombia (possibly 

 of Miocene age). The S. pictorum of Sowerby (Thes. Conch.) is a typical 

 specimen of princeps from Isla la Plata (the type locality). As also noted 

 by Hertlein and Strong, the pictorum of Chemnitz, 1784 was based on a 

 badly worn specimen showing little surface sculpture and said to be from 

 the Aegean or Mediterranean seas. S. unicolor Sowerby, described without 



