S. W. Ford—Two new species of Primordial Fossils. 125 
transverse section of the inner wall and the impression of a 
considerable portion of the outer wall. The latter shows that 
the external surface when perfect was longitudinally furrowed 
as in Archeocyathellus. In that genus, however, so far as 
known, there are two rows of pores along each of the furrows, 
one on either side of the septa; whereas, in the present genus 
there appears to have been but one, and that placed 
directly on the line of the septa. The evidence of this 
consists of rudely circular holes placed at regular intervals 
along the middle of each furrow in the cast. ese ap- 
pear to me to argue the existence of funnel-like projections 
mward of.the outer wall at the place of the openin t 
they mark the position of orifices leading into the interior ap- 
ears to me in the highest degree probable. Their position is, 
owever, so remarkable, that I was for a long time unable to 
understand the meaning of them. 
On one side of the specimen there are a small number of the 
interseptal moulds that project beyond the others and one of 
these shows one of its lateral faces for a considerable distance 
lengthwise, and also nearly down to the outer surface of the 
inner wall. An examination of this face shows that the cavi- 
ties observed along the furrows extend but 
a short distance inward, and that the septa 
arched around the funnel-like projections which 
they represent from below, striking the outer 
wall only at the intervening spaces (the spaces 
between the dots in the figure). It is further 
shown that these cavities are directed slightly 
the orifices were proportionally considerably larger than those 
ies of Are ellus (A. Rensselaert- 
cus), while their position is such as to present no obstacle in 
the way of regarding them as having communicated simulta- 
neously with two of the interseptal spaces. — 
The fossils of this group have, in their septate structure 
* Fig. la.—A few of the interseptal moulds of Protocyathus rarus enlarged to 
show the position of the suppest external orifices; 6, enlarged outline of a lat- 
eral face of one of the moulds designed to show the direction of the cavities c, c. 
