26 \. UffTHOGHl 



furnished with an elegant pattern of SphfiKToidal tubercles and chains 

 of granules in lim-s di\ rririni: from the rid-e. Poterior valve hav- 

 16 mucro subeentral ami suhroii.spicuous. 



Interior roseate or white; the acute and lobed margins of the 

 val\- arated, lanre, with a single slit on each side, the 



annulate; sinus lar^e, flat ; very delicately wrinkled in the cavity 

 of the ridge, laminated under the beaks. Posterior valve hexagonal, 

 with two posterior slit-. 



Girdle copiously adorned with translucid, erect spicules, and at 

 the fr<nt and hind ends and sutures having tufts of spicules or 



' r O 

 L- n-tli 4, breadtli 1 ], alt. ' mill. 



Mn-.'itliin, on Spondylus calcifer (Liverpool Coll.) 



I -mfhor/iit,* <ifr't<ionites CPR., Catal. of Ma/atlan Shells, p. 198 

 (1857.) 



Win-tiler th- varied coloring of this shell, its elegant sculpture, 



the l>ird-like form of the medial or hexagonal shape of the bifissured 



inal valves, or the adornment of the mantle with the transparent 



needle-like hairs, ri-ini: now in tufts, now in irregular crystals, be 



.im-d under the microscope, it would be difficult to find any 



shell of such surpassing beauty. Only one perfect specimen was 



found, but fresh valves belonging to several other individuals were 



detected amonir the Spondylus washings. The valves in the same 



shell L r reatly differ in color as in L. <iU>oJineatus. The posterior 



valve is peculiarly exquisite in its form, color and sculpture. There 



is considerable variation in the size of the tubercles and in the stria- 



>f the jugiim. ((', 



A. RHODEU8 IMNbry. n. -j). PI. 12, figs. 48, 49, 50, 51. 



OI.IMMI:, the expo.M-d portion of the valves about one-third the 

 entiiv width of the animal. Valves depressed, obtusely earinated. 

 led apices roseate. 



'i)>i,,< (l - almost *rjnirnt"t hit //- 



in' nt <>f flu- '/:,'!/' et; a heart ->hapi-d or .-ubtrianirular 



area remaining exposed. Dorm if l>nu<1 slim-phi tlrfimil mi<l $tr<>n<i/y 



ited froin ' i narrow, sliininir, baying slight 



\gitudinal tirito. Latej-o-plnn-al or >ide area* 



'// rOUnded*OWjU OOncaV&topped c/n-ntii,n.< arranged ill 

 'lei to the ridL'e. becomiiiL' radial and then irn-^ular at 



