296 MAZATLAN UNIVALVES 



FAMILY CAPULID^. 

 GENUS HIPPONYX, Defr. 



Cochlolepas, Klein. 1753 : H. fy A. Ad. Gen. vol. i. p. 373. 

 (Non Concholepas, Lam.) 



\ . 346. HlPPONYX SEBRATUS, n. S. 



If. t. conicd sew depressd, alba ; apice decollate, subcentrali 

 seu valde remoto, interdum valde prominente ; lamellis crebris, 

 acutis, extantibus, basi parallelibus, concentrice ornatd ; apicem 

 versus radiatim costatd ; supra lamellas radiatim tenuissime 

 sulcatd ; basi latissimd, planatd, lamellis creberrimis instructd ; 

 lamellis profunde serratis, lobis subquadratis ; inter lamellas 

 epidermide fused copiosissime indutd, t&niis incisis conferta ; 

 cicatrice musculari transversim corrugatd. 

 Proc. Zool. Soc. 1856, p. 3, no. 2. 

 ?=Hipponyx foliaceus, Mke. in Zeit. f. Mai. 1851, p. 36, 



no. 129, non Quoy fy Gaim. 



Tkis well marked species differs from H. antiquata, Linn. 

 in the character of the base, which is broad and flat, made up 

 of very numerous, close-set lamellae, deeply serrated into large 

 scarcely rounded lobes. The interstices are filled with epider- 

 mis, in irregular ribband-like shreds as in Byssoarca Pacifica. 

 The exterior, which rarely displays its characters satisfactorily, 

 has slight tubercular ribs near the apex, which are continued 

 over the lamellae as very fine, rather distant, indented striae. 

 The apex is sometimes flat, sometimes high and curved back 

 as in Emarginula rosea. It is always decollated and eroded. 

 One extremely young specimen has the minute helicoid apex 

 adhering to the spreading, rounded shell. The shelly base is 

 almost always very thin and smooth, sometimes scarcely per- 

 ceptible. It is nearly related to an Australian species, probably 

 H. foliaceus, Quoy ; but in that species the lamellae are serrated 

 outside with the strong radiating sulci ; the tobes of the basal 

 laminae are more rounded; and the epidermis is finer and 

 lighter. The largest specimen measures (from the very pro- 

 jecting apex) long. '96, lot. '94, alt. '46. 



A very flat sp. '86, '78, '25. 



A very conical sp. '68, "73, *43. 



Hab. Mazatlan ; gregarious, attached to each other, or on 



shells, (Byssoarcae, &c.) rare ; L'pool Col. 



