CHITON. 17 
ChHitow ruber. 
As our author owned but few Chitons, of which this was one, 
the recognition of it in his cabinet is very easy, since it is the 
only shell which can possibly agree with his description. The 
surface of the specimens, which belong to the species similarly 
named by almost all writers (Brit. Moll. pl. 59, f. 6), aptly 
coincides with the expression, “ valvulis oblique subarcuato- 
striatis.”’ 
Chttow albus. 
By a similar process to that used for the last species, one 
may recognise the Chiton albus in the Linnean collection ; it is 
the little Chiton thus named in Sowerby’s ‘ Conchological 
Illustrations’ (fig. 99). The specimens explain the expression, 
“valvula prima postice emarginata,” that hinder edge (which is 
always more or less incurved in this genus) being more sud- 
denly concave in the middle than is the case in the individuals 
of the next, and most closely allied, species in company with it. 
Strictly speaking, the surface is not smooth; but it requires a 
powerful glass to detect the very minute shagreening. ‘Acta 
Nidros. 3, t. 6, f. 4,” (an irrecognisable figure of a small Nor- 
wegian Chiton) is cited in the manuscript. 
Chitow cinereus. 
With equal readiness, and by a like method, one may identify 
the typical examples of this species: they are assuredly the 
marginatus of British writers, (C. cinereus, Brit. Moll. pl. 58, 
f.1). One of the two small individuals present in the col- 
lection (“ vix cimice major”) is “ ovata;” the other strikingly 
displays the ‘seu postice paullo latior” of the description. 
“Forte prioris varietas” is written in the Linnean copy, and, 
D 
