54 Couthouy's New Species of Mollusca 
found upon our coast. There can at present be but 
little doubt, that even so accurate an observer as the 
lamented Say has erred in describing as new many 
species previously well known to European naturalists. 
Nor is this at all surprising, when we consider the difti- 
culties under which, in common with ourselves, he 
labored, in not possessing specimens from their coasts 
for comparison; and the paucity of satisfactory works 
on this branch of natural history to be procured in our 
country at the time he wrote,—defects which even yet 
are most sensibly felt by us all. 
Of the difficulty of determining species from descrip- 
tions alone, where, as in many genera, the specific differ- 
ences are so slight, it is hardly necessary to speak ; and 
the uncertainty of judgment founded upon figures alone is 
perhaps still greater. I have therefore preferred furnish- 
ing a full description and applying a specific name of my 
own, wherever there appeared to exist reasonable grounds 
for so doing. It seemed to me advisable, where the point 
was doubtful, to risk rather the addition of a synonym 
to a known species, than to apply existing names to 
such as were actually new. 
It may here be stated, that of the Annulata, two 
species of Amphitrite and one of Sabellaria have been 
found in our vicinity; but not having been able to 
decide with any certainty upon their being described or 
not, they are not here included. I am inclined to refer 
one of the Amphitrite to the penicillus, Lk. 
'TusuLARIA INDIVISA, Ellis? 
'T. indivisa, Ellis Coral. p. 31. t. 16, f. C. ! 
Tubularia calamaris. Pall., Elen. Zooph. p. 2. No. 38. 
