NO. 2 ROST: THE FAMILY ARCIDAE 187 



while in B. reeveana it is always bright yellow. The edentulous gap in 



the hinge seems to be more pronounced in juvenile specimens than in 



adults. 



Occurrence: The species is reported from 4 to 15 fms on different kinds 



of bottom. However, it seems to live attached to rocks or other hard 



substances (shells, etc.). 



Distribution: Punta Penasco, Sonora, Gulf of California, Mexico, to 



Ecuador. Also found in the Pleistocene in Bahia de la Magdalena, Baja 



California ( Hertlein and Strong, 1943). 



Subgenus FUGLERIA Reinhart 1937 



Fugleria Reinhart, Jour, of Paleontol., vol. 11, no. 3, 1937, p. 184. 

 Type of subgenus: Barbatia {Fugleria) pseudoillota Reinhart 1937, 

 Pliocene, (orig.) 



Barbatia (Fugleria) illota (Sowerby) 1833 

 PI. 11, figs. 6-8 ; text-figs. 83 a-c 



Byssoarca illota Sowerby, Proc. Zool. Soc. London, 1833, p. 18. 



Syn.: Area tabogensis C. B. Adams 1852. 



Fig.: Reeve, Conch. Icon., vol. 2, Arcaj species 78; Maury, 1922, PI. 



2, fig. 8. 

 Type loc. : Golfo de Nicoya, Costa Rica ; under stones. 

 Holotype: British Museum? 



Remarks: Reinhart (1937) placed this species in the subgenus Fugleria. 

 The posterior teeth, according to him, are totally absent in the type of 

 the subgenus, but in Barbatia illota they are well developed (PI. 11, 

 figs. 6-8). As may be seen from the illustrations, both the posterior and 

 the anterior teeth are distinctly striated. The teeth in the center of the 

 hinge become granular and very irregular with increase of size; some- 

 times, especially in specimens of great length, they become quite obsolete 

 for a long distance in the center of the hinge (PI. 11, fig. 6). 



The ligamental area is relatively narrow and the flattened anterior 

 part is covered by a horny light brown periostracum. In young speci- 

 mens the ligament consists of a few grooves (two in a specimen of 17 

 mm length) posterior to the umbones. In larger specimens, the grooves 

 develop in both directions and become V-shapcd, as in Cucullaearca (see 

 Maury, 1922, p. 20), though not as pronounced as \x\ this subgenus; the 

 apex of the V lies just under the umbones. One specimen of 23 mm 

 length has three V-shaped grooves, two of them reaching the hinge line 

 before the umbo; another, measuring 35 mm in length, 24.3 mm in 



