APPENDIX. 87a 
On Prcruncuuuts (p. 162). The name P. glycimeris (p. 163) must 
be changed to P. violascens, or, perchance, to P. pallens (Arca p. 
Lin.); the author’s statement relative to the Linnean types, both 
here and at page 162 (note to P. pilosus), having been an error, the 
result of too hasty an examination. Consult Zeit. Mal. 1846 
(P. hirtus, Ph.), and ‘ Malacologia Rossica’ (P. septentrionalis, 
Mid.). ; 
Pectunculus Siculus, p. 162, t. 19, f. 19 ... P. undulatus, p. 162, 
t. 19, f. 26... P. stellatus, p. 163, t. 19, f. 31... P. violascens (as 
P. glycimeris, p. 163), t. 19, f. 20 ... P. intermedius, p. 164, t. 19, 
P5231”... 22 ovatus, py 1040. 19) f. 23) 0 PS tineatus, op. 164, 19, 
f. 32 ... P. maculatus, p. 164, t. 19, f. 34 ... P. giganteus, p. 164, 
tM. 33.0... Pevadians,p. 16554. 19; £:25....... P. vtireus,p. 165, 
t. 19, f. 28 ... P. multicostatus, p. 165, t. 19, f. 36 ... P. parcipictus, 
p- 165, t. 19, f. 35 ... P. aurifiuus, p. 165, t. 19, f. 37 ... P. tessel- 
latus, p. 166, t. 19, f. 23, 38 ... P. morum, p. 166, t. 19, f. 43... 
P. oculatus, p. 166, t. 19, f. 89 ... P. nodosus, p. 166, t. 19, f. 50... 
P. pallium, p. 166; t. 19, f. 41... P. bieoter;.p> 166, t.:19; f.42: 
PrEcTUNCULUS sPADICEUS (t. 19, f. 18), Reeve, Z. P. 1843, p. 189; 
I. Pect. f. 47. Transverse, suborbicular, equilateral, thick, ventri- 
cose, chestnut-brown or tawny brown, concentrically incised by 
minutely waved crowded striz, that become still more dense as they 
recede from the umbones, and are subdecussated laterally by fine 
almost obsolete radiating striole which pervade the entire surface in 
young individuals; ventral edge strongly toothed, much and evenly 
arcuated: beaks acute, not inclined, almost in the middle of the rather 
small and somewhat narrow ligament: inside white; hinge-margin 
broad; teeth large, moderately numerous. 14. There are traces, or, 
as it were, shadowingys out, of radiating ribs. 
PEcTUNCULUS TENUIcosratus (t. 19, f. 24), Reeve, Z. P. 1843, p. 80; 
I. Pect. f.35. Suborbicular, equilateral, ventricose, rufous, obscurely 
mottled with white, radiated throughout with very numerous rather 
distant thread-like rounded costelle, which are crenated, sharply 
elevated and far apart (except the extreme ones); their intervals 
exhibit, under the lens, a minute similar, yet still more crowded and 
decussated, sculpture; ligamental margin rather short; umbones 
rather prominent; beaks scarcely inclined, in the middle of the liga- 
ment; inside whitish, somewhat stained with brown ; teeth numerous. 
14. China; Australia. When mature is angulated on one side. 
The epidermis is arranged in 3 or 4 rows between the riblets. 
PectuncuLus PrctinoweEs (t. 19, f. 27), Desh. in Cuv. (ed. 1836), 
t. 87, f. 8.—Reeve, I. Pect. f. 44. Lenticular, depressly convex, 
radiately ribbed; ribs somewhat oblique, compressed, depressly flat, 
with the interstices delicately excavated; fleshy white, profusely 
