24 
PALEONTOLOGY OF NEW YORK. 
an inch. Tube composed of conical imbricating rings, about forty in the space 
of one inch (about four in the space of one-tenth of an inch), giving the tube a 
strongly annulated appearance. 
“ The specimen figured exhibits the tubes of more than thirty individuals of 
Conchicolites corrugahis, attached to the spire of Cyclonema bilix, Conrad. 
“ From Conchicolites gregarius, the present species is distinguished by its 
greater average length and much greater diameter, by its much less closely 
crowded habit, and by its much more strongly marked annulations. 
“ Locality and formation. Attached to the shell of Cyclonema iPleurotomaria) 
bilix, Conrad, from the Hudson River group (Lower Silurian), of Cincinnati, 
Ohio. 
“ Ortonia minor. Nidi.— Apec. Char. Tube calcareous, solitary attached by the. 
whole of one side to some foreign object. Length of tube from one-tenth to 
three-twentieths of an inch; diameter at mouth from one-twentieth to one- 
twenty-fifth of an inch. Tube marked with transverse ridges or annulations, 
which are sometimes faintly marked on the side opposite to the attached sur¬ 
face, and the number of which is fifteen in one-tenth of an inch. Tube in 
general strongly curved toward its smaller extremity (pi. iv, fig. 3), (2). 
“ Though often occurring in great numbers together, the tubes of Ortonia 
minor, like those of Ortonia conica, are strictly speaking solitary; that is to say, 
they do not, like the tubes of Serpula or Conchicolites, interfere with one another 
or come into contact except accidentally. The tube is generally jiretty nearly 
circular in section, though sometimes slightly trigonal, conical, and always 
more or less curved. Sometimes it is simply curved like a horn; sometimes it 
is curved like the letter S, and sometimes tlie smaller extremity is twisted into 
a flat spiral. I can detect no longitudinal striation, but the tube is covered 
with very numerous transverse ridges (at least 150 in the space of an inch), 
which are generally better marked on the sides than on the back of the tube. 
In very small, presumably young, specimens, I have been unable to deter¬ 
mine the existence of these ridges, and even in fully-grown examples they are 
more strongly marked in some than in others. The tube is always attached 
along its whole length, and in no case is any portion free, as is the case in 
Conchicolites. 
“ Locality and formation. Common in the Hudson River group (Lower Silu¬ 
rian) of Cincinnati, Ohio, attached to the exterior of Brachiopods and Corals.” 
