422 Mr. P. H. Carpenter on certain Points in 
the visceral cavity (except as regards the number and ar- 
rangement of pieces).”’ 
One scarcely knows how to criticise the remarkable state- 
ments contained in the passage just quoted. For myself, I 
should greatly like to learn something more about the 
evidence which satisfied Dr. Hambach that the structures in 
question are “ Bryozoa or ovulum-like bodies.” If they be 
Bryozoa, they must certainly represent a most aberrant type 
of that group, and it would be well worth Dr. Hambach’s 
while to investigate and describe them. If, on the other 
hand, they are “ ovulum-like bodies,”” one would like to know 
more about the “ovulum” which they resemble. Does Dr. 
Hambach mean to suggest that they are partially hatched 
“ovula” of the Blastoid ? 
After Dr. Hambach’s astounding statements about the 
summit-plates of the Blastoids, his remark that this group 
has ‘‘ unquestionably most affinity” with Echinoderms falls 
rather flat, as I am not aware that any one has ever proposed 
to consider these fossils otherwise than as members of that 
subkingdom. As a general rule, too, the nearest allies of the 
Blastoids have been sought for among the Crinoids. But, 
according to Dr. Hambach, the affinity of the Blastoids with 
Echinoderms “can easily’ be comprehended if we divide the 
calyx into two equal halves, ¢. e. an upper or dorsal and an 
under or ventral one, of which the ventral one would be com- 
posed of the pelvis and fork-pieces, and the dorsal one of the 
deltoid pieces and ambulacral fields. Supposing the column 
to be absent, we would have an analogue of an Hchinus, 
except that mouth and vent are placed, together with the 
ovarian openings, on the dorsal part of the shell instead of 
being on the ventral side, as in true Echinoids.” 
I must confess that I cannot easily comprehend the advan- 
tage of inverting the generally received nomenclature in such 
a manner as to place the mouth and vent of a Blastoid on its 
dorsal side; and when this is done and the column supposed 
to be absent, I altogether fail to see the analogy between the 
Blastoids and the (true) Echinoids, in which last group Dr. 
Hambach admits that the mouth and vent are on the ventral 
side. Hvenif I am right in supposing that the word ‘‘ Hchino- 
derms”’ in the passage quoted above should be read “ Hehi- 
noids,” I am unable to see the affinity between this group and 
the Blastoids, “ both as regards the calcareous shell as well 
as the interior of the visceral cavity (except as regards the 
number and arrangement of pieces).” Ii the pieces of the 
calcareous shell in the two groups do not agree in number and 
arrangement, I should be glad to know the characters wherein 
