Jan , 1914.] 
.4 Starfish found in Adams County. 
223 
The aboral side of the rays and disc, as far as can be made out, 
is rather less regular than the small portion of the aboral side of 
P. dyeri figured. When one picks out the dorsolateral plates 
with a lens however many of them are of the same quadrangular 
type illustrated for P. dyeri. There is also a central depression 
on each of these plates for the insertion of the spine as in P. dyeri. 
It is possible that there are some shorter, slighter pieces which lay 
between the rows of quadrangular or triangular plates. 
Fig. 2. Promo-palaeaster dyeri Meek (?) Natural size; ventral view 
part of disc and arms. 
The crushing down of the arch of the aboral skeleton and the 
mixing the broken spines from the surface in with the plates 
makes it difficult to state precisely how many rows of dorsolateral 
plates intervened between the supero-marginal plates and the 
indistinct carinals which occupy the mid-dorsal line. The modem 
starfish does not have as many dorsolateral plates as another 
Richmond starfish, Palaeaster magnificus Miller, has. In this 
respect my specimen seems more like the recent Asterias. 
The ambulacral plates seen from below are naturally partly 
covered by adambulacral plates. There are, however, three 
ambulacral plates at the end of the shorter arm which have lost 
their adambulacrals. These are 5 m. m. long and a little more than 
a millimeter wide. The locations of the pores through which the 
tube feet passed are easily distinguishable. These pores seem to 
alternate so that each half of the ambulacral groove would present 
two rows of tube feet. This alternation is only apparent as there is 
but one tube foot in the opening between two consecutive ambula¬ 
cral plates and one plate between two successive pores. The 
device is correlated in the recent starfish, with a more rapid loco- 
