756 CLASS XII. 
Kenntniss wirbelloser Thiere, Braunschw. 1847, 4to, 8s. 46—53). They are, 
according to QUATREFAGES, of distinct sex, but the male individuals are 
much rarer than the female. 
For the distinction of species recourse is had amongst other characters to 
the form of the two small shovel-shaped calcareous plates which are placed 
below on the mantle, at the base of the trachez, and are commonly named 
palmule. One species, famous for the injury it caused to the piles of the 
dykes in Holland, in the beginning of the last century especially, might be 
named Teredo Sellii (Teredo navalis L. et auctor. in part, Teredo batavus 
SPENGLER). It is figured in the work of Se~iius and in BLUMENBACH 
Abh. naturhistorischer Gegenstinde, No. 89. The palmule are fixed on a 
short pedicle, inversely triangular, and terminating at the broad end on 
each side in a point. Piles that had been driven only six or seven weeks 
previously were seen to be entirely eaten through by this worm, and robbed 
of all their strength. In this way the island of Walcheren was in 1730 
threatened with destruction. From time to time the same mischief was 
discovered in other places, especially on the Zuiderzee near Medemblik, 
Lambertshagen, &c.; West-Friesland was forced in consequence to mask 
its dykes with large stones, which being brought into the country from 
abroad, occasioned a great expense; according to Marrinet, Catechismus 
der Natuur. 111. bl. 33, f. 5,600,000 were applied to the first repair of these 
dykes. Since the middle of the last century the mischief has much diminished, 
so that hence may be explained the fact, that even in the national museums 
only a few specimens of Jeredo are preserved. This injury to our dykes 
was the occasion of many writings, which however contributed little to 
the advancement of science. We suffice ourselves with citing the large 
work of G. Sexuius, Histor. nat. Teredinis. Traj. ad Rhen. 4to. Fossil 
Teredines also are found in the tertiary formations and in the chalk strata. 
Septaria LAM. 
Sp. Septaria arenaria Lam., Serpula polythalamia L., Rumen. Amb. Rari- 
teitk. Tab. 41, figs. D, E. -A long conical tube, with irregular constrictions 
and corresponding septa projecting internally; at the thin end are two 
calcareous pipes. The description of Rumpurus already indicates that the 
enclosed animal has much agreement with Zeredo. This was confirmed by 
the discovery of a similar species in the Mediterranean a few years ago by 
MatuHéron (Septaria mediterranea Dusu. Conchyl. Pl. 2, figs. 9,10). The 
animal with its small shell is contained in the tube that sticks in the 
sand. Perhaps this genus might be united with Teredo, as has been the 
Indian species figured by Homz under the name of Teredo giganteus (Phil. 
Transact. 1806). 
Family XXIII. Tubicola. Mantle sacciform, cloven ante- 
riorly for the passage of a rudiment of foot; two trachez conjoined 
into a fleshy pipe. Animal clavate anteriorly. SBivalve shell 
gaping, without cochleariform process, with hinge edentulous 
linear, contained in a calcareous tube, or concrete with the wall of 
the tube. 
