﻿204 DEVONIAN FAUNA. 



material at hand is often quite insufficient to show how far their variation is only 

 accidental or of permanent value. On the other hand, as fresh specimens are 

 examined, the existence of real lines of demarcation becomes increasingly evident. 

 Hence, while it is possible that some of the species now given may have here- 

 after to be re-united, it seems probable that the number of species will be 

 ultimately found to exceed that which is here recorded. 



1. Capulus? invictus, n. sp. PL XIX, figs. 12 — 14. 



Description. — Shell rather small, depressed, lenticular, regularly coiled. Spire 

 small, contiguous, almost flat but tending upwards, nearly level with the highest 

 plane of the shell, rapidly and regularly increasing, consisting of one or two 

 volutions. Apex minute, recurved, pointed. Body-whorl wider than high; in 

 section suboval or subtriangular, gently rising from the inner or sutural side, 

 spreading out for a great width above, where it is slightly convex and on the 

 whole oblique, rounding so very rapidly as to be almost subjugular on the narrow 

 back, and then proceeding inwards in an oblique direction to the lowest part of 

 the shell, where it curves upwards to form apparently an incipient umbilicus; 

 longitudinally, regularly arched, almost keeled on the back, and bearing a more or 

 less defined, broad, shallow groove, midway between the convex back and base of 

 the shell. Mouth oblique, the lower part being less advanced than the upper. 

 Peristome in part wavy or coarsely undulated. Surface ornamented with 

 numerous, superficial, unequal, angulated, broad, flat spiral bands, separated by 

 shallow grooves. Colour black, with broad white spiral bands, following the 

 course of the grooves. 



Size. — Height 12 mm., width 21 mm. 



Localities. — From Wolborough there is a specimen in Mr. Vicary's Collection ; 

 and from Barton and Lummaton two in the Lee Collection in the British 

 Museum, one in the Woodwardian Museum, two in the Bristol Museum, and two 

 in my Collection. 



Remarks. — Whether this species is to be regarded as belonging to Capulus, or 

 to Platyo stoma, I am not sure. It appears at all events to be on the border-line 

 of the former genus, its regular symmetrical shape closely connecting it with 

 ordinary spiral forms. 



Mr. Vicary's specimen is the only one in which the ornamentation or the 

 colour-bands are visible, but in it the portions of the bands not worn away are 

 beautifully displayed. The other specimens seem smooth ; but, as their surface is 

 not well preserved, there is no reason to doubt that they belong to the same 



