344 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxxv. 



posteriorly, forming a sort of buttonhole effect. A portion of these 

 fissures shows on the right side. 



The thickened granulate line which forms the postero-lateral border 

 of the carapace is continued across the posterior margin. 



Measurements. — Length of carapace, 30.5 mm. ; extreme width at 

 the eighth tooth, 44.2 mm. ; fronto-orbital width, 16.5 mm. ; width of 

 front between the inner orbital angles, 8.6 mm. 



While in form this species resembles C. magister more than any 

 other recent Californian species, yet C. magister has more prominent, 

 triangular side teeth, 10 in number, its orbital fissures are linear, and 

 the postero-lateral margin is discontinuous with the posterior margin. 



The bed containing the crab consists of fine conglomerate and 

 coarse sand, and contains the following fauna : 



List of fossils from lower Etchegoin formation (upper Miocene). Henri/ Springs. 

 .'/ miles south of Coaling't, California. 



ECHINOIDEA. 



Echinarachnius gihhsii R£mond. 



PKEECYPODA. 



Area trilincata Conrad. Mulinia densata Conrad. 



Clidiophora punctata Carpenter. Panopca generosa Could. 



Diplodonta harfordi Anderson. Solen cf. siearins Gould. 

 Glycym eris, species. 



GASTEROPODA. 



Nassa California n<i Conrad. Pisania aff. fort is Carpenter. 



CIRRIPEDIA. 



Balanus coneariis Bronn. 



Family PARTH ENOPID^E. 



Genus BRA NCH IOL.AMBRUS, new. 



Carapace rhomboidal, very convex in an antero-posterior as well 

 as in a transverse direction. Branchial regions very extensive and 

 nearly touching each other at the median line. Front and antero- 

 lateral margins dentate: postero-lateral margin a sinuous line, below 

 which the surface is steeply inclined. 



Appendages unknown. 



(J3pdyxta, gills, branchiae, in allusion to the extent of the branchial 

 region : Lambrus, until recently the name of a genus of crabs.) 



Type of the genus. — Branchiolambrus alius, new species. 



