® 
348 MAZATLAN UNIVALVES 
397. LiToRINA ASPERA, PAzl. 
Proc. Zool. Soc. 1845, p. 139: —Abbild, pt ui. pl. 4, f. 13.— 
Mhke. in Zeit. f. Mal. 1847, p.178, no. 2: do. 1850, p. 163, 
no.8.—C. B. Ad. Pan. Shells, p. 170, no. 5. —?? Midd. Mal. 
Ros. pt. 11. p. 66, no. 10. 
Melaraphe aspera, H. § A. Ad. Gen. 314. 
Besides the natural doubt that an essentially tropical shell 
extremely common at Panama, less so at Mazatlan, and not 
found at all on the Californian coast by the accurate observer, 
Mr. Nuttall, (where it is replaced by L. planaxis,) should 
reappear in the Boreal region of Sitcha, the description of — 
Middendorff by no means accords with Philippi’s shell. The 
Russian shell is “‘crassa, lineis nigricantibus obliquis picta, anfr. 
parum convexis,” and is said to resemble L. ziezac and L. zebra. 
The evidence therefore appears to be very unsatisfactory, on 
which Prof. Forbes, in his Zoological Map, gives this species 
as characteristic of the Oregon fauna. A very different shell 
from Pernambuco (J. P. G. Smith) is also given in the B. M. 
as the L. aspera, Phil. 
The Mazatlan shell is (for the genus) rather thin, and toler- 
ably constant in characters. It is readily known when fresh 
from L. conspersa by the dark hue and sharp, distant ribs. In 
shape it goes through the same changes as its congener; but 
m sculpture and colour is mach more constant. The ribs are 
sharp, with very broad concave interstices, are somewhat rough- 
ened by lines of growth, and are beautifully tinted, in ill-defined 
spots, with umber. The young shell (as Mke. states) has a 
ehaleedonic apex like that of L. conspersa, below which it has 
generally a slate coloured band. The spots also are more de- 
fined, and run into lines. They were provisionally distinguish- 
ed by Mke. as L. apicina. At this pegiod the ribs are closer 
and flattened, but still much more conspicuous than the cor- 
responding stage of L. Pnilippii. The apex is commonly eroded 
in the adult. The colour within resembles that of L. conspersa, 
but is generally darker. The base of the young shell also 
agrees in being often keeled or angulated. The operculum is 
rather broader than in that species, with the thin trasparent 
edge less defined. Inside the nucleus is raised, and is rarely 
seen to display the spiral elements. The muscular sear is not 
furnished with spiral strie, but is irregularly roughened with 
minute knobs and strie of growth. An unusually compact 
specimen measures long.'7, long. spir.°34, lat. *5, div. 70°. 
An elongated sp, pei 04s Fs ‘308 ea eee. 
