452 DR. E. P. WRIGHT ON A NEW GENUS OF TEREDININ.E. 
tide very slightly brackish; but one must go many miles further down ere meeting with 
the sea, the distance from which to Mandarapore is more than seventy miles. The 
influence of the tide, forcing back to some extent the current of the Ganges, is felt, it is 
true, even higher up, especially during the rainy season, when the river is swollen, but in 
the summer it is by no means so perceptible. 
The water of the river Comer is not only considered perfectly fresh, and as such used for 
drinking, but it is also a soft water, and used very extensively for washing and all other 
. household purposes. On a bend of this river Mr. Dunlop had a small boat-house, and in 
the proximity of this house several trees had been cut down, one or two of which falling 
into the river were allowed to stay there, and some time afterwards Mr. Dunlop perceived 
that portions of these trees which lay exposed during a very dry summer were perforated 
by some animals. He at once had the portion that was still under water examined, 
and succeeded in extracting two nearly perfect specimens of a Teredo-like mollusk. The 
specimens now in my possession were removed by Mr. Dunlop himself, the trees were 
still almost iv situ, and the water of the river fresh; so I think there can be no reason- 
able doubt that these shipworms were veritable inhabitants of fresh water. It appears 
that they are well known to the Hindoo fishermen, who meet with them even higher up 
the Ganges. The plan they adopt to destroy them when they attack their boats is to 
suspend the boat infested across two upright poles and to light a fire beneath it, which 
in a short time destroys all the mollusks, and by slightly charring the timber hinders for 
some time a second attack. 
I cannot find any previous record of a freshwater Teredine. The Teredo Senegalensis 
of Blainville is not, so far as I can see, any exception to the general rule of their being 
inhabitants of salt water. The species described in this paper, however, is referred to by 
Mr. Jeffreys in the * Report of the British Association for 1860’ *. 
Genus NAUSITORA, nov. gen. 
Testa globosa, regularis, e valvis duabus eequalibus, curvatissimis, bilobatis, quarum 
facies externse striate. Sine cardine vero. Ligamentum rudimentale. . Valvarum 
pars interior processu lato curvato et insuper lamella accessoria lata instructa. 
Animal vermiforme. Pallium tubulatum. Siphones longissimi, ad finem bifurcati; 
quorum foramina fimbriata. Palata siphonalia longa; interior corporis facies plana; 
exterior convexa; stipes longus, curvatus, acutus. - 
Hab. Flum. Comer, prov. Bengal. 
Mus. Brit. et Coll. Sancta et Individ, Trinitatis, juxta Dublin. 
Shell globular, regular, composed of two equal, much curved, bilobed valves, their 
outer surfaces striated. No true hinge. Ligament rudimentary. Interior of valves fur- 
nished with a broad curved process and also with a broad accessory plate. : 
Animal vermiform. Mantle tubular. Siphons very long, bifurcated at their extremities ; 
orifices fringed. Siphonal pallets long; inner surface of body flat, outer convex; stalk 
long, curved, and pointed. | 
* Report of the Oxford Meeting. "Transactions of the Sections, p. 117. 
