154 ROCHESTER ACADEMY OF SCIENCE. | March 23, 
specific names; these were not found in any work accessable to me, and 
I have only given such information as I could find. 
In no group of mollusks is the specific distinction more difficult of 
determination than in the Muricidae; shells inhabiting a sandy or 
muddy, sheltered locality, will be thin and elegantly frilled, while the 
same species from a rocky, exposed locality will be thick and almost 
smooth. The degree of spinose development is no criterion, inasmuch 
as a series of specimens from a single locality will show every degree 
of development, from simply nodulous to the most pronounced condition 
of spinosity. The soft parts in many species are nearly identical, but 
the opercula show some very good characters. 
The larval shell, or nucleus, appears to afford good specific 
characters, and I have availed myself of this feature in many cases. 
Unfortunately the specimens are usually received by the student in an 
imperfect condition, and almost invariably with the apex either broken 
off or eroded. In a lot of 250 Murex brandaris recently examined by 
myself there were but ten specimens with a perfect apex, and in a lot 
of 200 Murex adustus, not a single specimen was perfect. These spec- 
imens were received direct from the original collectors and had not 
been tampered with by middlemen. This illustration shows the diffi- 
culty under which the student works while studying this interesting 
branch of Malacology. 
There are doubtless many who will disagree with me regarding 
some of the species admitted in this catalogue as valid, which have 
been by Tryon and others included in the synonomy, or as varieties of 
other allied species. In the present catalogue I have admitted as valid 
any species which can be distinguished from another by good charac- 
ters, and which is not seen, in an abundance of material, to inter- 
grade into other forms. 
During the past ten years several European conchologists have 
separated certain species of the family into sections, but they are not 
stable, and the characters used merge into each other so that it is impos- 
sible to determine just where certain of the species belong in these 
sections. As an example of this splitting up I cite the gerus Z)p/zs, 
which is divided by Jousseaume into twelve sections; there are but 
fifteen species in the genus. Such work seems to me hardly worthy 
the consideration of the true conchologist. Our science is now over- 
burdened with generic, sub-generic and sectional names, and it is 
simply absurd to give a group name to every two or three species which 
happen to differ ina slight degree from their congeners. 
