Syn. Serpula heptagona, Morris, Catal. 66. Den- 
talium elephantinum, Brawler, 1 l.pl. \ .f. II. 
1 his curious Serpula in the young state, which is rare, 
much resembles A. crassa (tab. SO.), but is distinguished 
by showing indications, first of two, and soon afterwards 
of two more keels, besides the dorsal one, making with the 
edges of the base in all seven angles; it is also rougher 
and more conical. The seven angles become equal upon 
the free shell. The operculum varies much in form, as 
shown in the figures a. and b. 
Brander has confounded the free form of this Serpula 
with Dcntalium costatum (tab. 70. fig. 8.) under the name 
of Dcntalium elephantinum. 
Not uncommon at Barton. The specimens figured are 
in Mr. Edwards’s collection ; we have the same species also 
from near Paris, sent to the late Mr. Sowerby by Mons. 
Defrance. 
SERPULA avita. 
TAB. DC XXXV.— /g, 1. 
Spec. Char. Attached throughout, gradually en- 
larging, variously curved, subcylindrical, with 
an expanded base and a dorsal keel, which 
forms a spine projecting over the aperture ; 
lines of growth arched ; edge of the aperture 
thin. 
Nearly related to the recent Serpula triquetra ( Vermilia , 
Lam.), but differing in having a thinner keel and smoother 
sides. 
Attached to a fragment of Inoceramus in chalk. Pre- 
sented by Mr. Sankey in 1819, who found it at Dover. 
