U6 AXEL A. OtSSDN 



Philippi's specimens of A. kindermanni were probably beach-worn to 

 an extent that their donacid characterstics were not immediately discernible. 

 Young shells have extremely thin valves, and if worn slightly may have 

 smooth margins and the shape and rayed markings of a young Tagelus. In 

 Thiele's Handbuch, the group is placed in the Psammobiidae. 



Donax (Amphichaena) culter Hanley Plate 59, figures 5-5b 



Donax culter Hanley, 1845, Proc. Zool. Soc. London, No. 13, p. 14.— Reeve, 1854, Conch. 



Icon., vol. 8, Donax, pi. 4, fig. 21 Gulf of California. 

 Donax californicus Conrad, var. D. culter Reeve, Sowerby, 1866, Thes. Conch., vol. 3, 



Donax, p. 310, No. 36, pi. 281, figs. 56, 57, only (not D. californicus Conrad, 



1837). 

 Amphichaena kindermanni Philippi, 1847, Archiv. f. Naturg. vol. 13, p. 63, tab. 3, fig. 



7 Mazatlan. 

 Donax petalHna Reeve, 1854, Conch. Icon., vol. 8, Donax, pi. 8, fig. 51. — Pilsbry and 



Lowe, 1932, Proc. Acad. Nat. Sci. Philadelphia, vol. 84, p. 132. (listed only). 

 Donax petalina Deshayes, 1855, Proc. Zool. Soc. London, p. 350. — Sowerby, 1866, Thes. 



Conch., vol. 3, Donax, p. 315, No. 63, pi. 282, fig. 86. 



Shell generally small (largest seen about 32 mm.), elongately subrhom- 

 boidal, tageloid, the ratio of height to length about 1 to 2, highest at the 

 beak which is placed a short distance back of the middle. Surface is finely 

 ribbed or radially striated, the finely grooved interspaces minutely punc- 

 tate. Color is a pale yellow and mauve, divided into wide rays, the interior 

 of the shell purple except under the yellow rays where it is white. Margins 

 are finely crenulated. 



Common as a beach shell at Acapulco, Mexico. D. bella Reeve, 1854 

 {op. cit. pi. 6, fig. 41, Acapulco) is probably this species also. 

 Range — Mexico. Mexico: San Ignacio; Sinaloa; Acapulco. 



Genus IPHIGEXIA Schumacher, 1817 

 Type species by monotypy, Donax laevigata Gmelin. 



Shell large or medium-sized, subtrigonal to elliptical with submedian 

 beaks, solid and porcellaneous, no lunule or escutcheon. The beaks are 

 generally placed a little behind the middle, hence the anterior side is a little 

 longer. Surface smooth or marked only with lines of growth and occasionally 

 fine, obscure radial lineation may be present overlain by a thin, yellowish to 

 olive-brown periostracum. The ventral margins are entire. Hinge has two 

 cardinal teeth in each valve, the right posterior and the left anterior tooth 

 being large and bifid, the others small and simple; lateral teeth are more 

 or less obsolete. Ligament external, wholly posterior, seated on or behind 

 a large, platelike nymph. Pallial sinus is ample, rounded at the end, and 

 extending a little beyond the middle of the cavity of the shell. Color of 

 shell under the periostracum is generally white, or suffused with violet 

 or purple, heaviest on the umbones. 



Iphigenia altior (Sowerby) Plate 60, figures 1, la 



Capsa altior Sowerby, 1833, Proc. Zool. Soc. London for 1832, pt. 2, p. 196. "Hab. in 

 Peruvia et America Centrali." Gulf of Nicoiyo; also a smaller variety at 

 Tumbez.— Hanley, 1843, Cat. Rec. Bivalve Shells, p. 86, pi. 14, fig. 34; also 

 p. 349.— Romer, 1869, Syst. Conchyl.-Cab., bd. 10, abt. 3, Donacidae, p. 114, 

 tab. 21, figs. 1-4. 



Iphigenia ambiqua Bertin, 1881, Nouv. Arch. Mus. Hist. Nat. (Paris), ser. 2, vol. 4, 

 p. 120, pi. 4, figs. 4a, 4b, 4c. 



