344 ^^^^ American Geologist. J""^- ^^o^- 
This group of blastoids presents some striking characteristics, 
and is further removed from Orbitremites (Granatocrinus) 
than Cryptobastus is. The base is either level with the lower 
ends of the ambulacra or decidedly convex. The basal plates 
form a low broad cup, thus separating widely the lower ends of 
the ambulacra. The interradials (deltoids) are rather large, 
often quite a third of the length of the fossil, while the anal 
plate is sometimes extravagantly produced upward to form a 
hood over the anal opening and pushing out towards the center 
so as to reduce the usual star-shaped central opening to a 
lunule. The spiracles are small and, although known for 
some time in Granatocrinus aplafiis, have been discovered but 
recently in Codonitcs inopinatus. They are hardly round in 
any of the species and decidedly elongate in the last two nien- 
tioned species, thus approaching, as we have alway^s suspected, 
the slits of Orophocrinus. 
The prominence of the radial or fork pieces along the 
sutures, gives rise to elongate depressed triangles bordering 
the ambulacra, and across these triangles the lines of ornamen- 
tation run as on the deltoids, or interradials, recalling the side- 
plate areas on Orophocrinus. The ambulacra are either even 
with the surface of the radials and interradials or stand out 
bead-like above them. 
The tops of the radials at the common suture are generally 
prominent and sometimes so much so as to give a strongly 
pentagonal cross section and a decidedly Codaster-like appear- 
ance to the specimen. 
The ornamentation is either linear, sometimes very fine and 
again cord-like in its coarseness, or toothed-linear and possibly 
granulo-linear. 
We propose for this little group the generic name of Lopho- 
hlastus in allusion to the crest-like hood over the anal opening, 
and make Codonitcs inopinatus the type species of the genus. 
We offer the following generic diagnosis: Body conoidal, 
elliptical or quite globose ; ventral side generally convex, but 
sometimes flat ; base large, flat or decidedly convex ; deltoids or 
interradials large, sometimes a third of the entire body length ; 
radials or fork pieces from one-half to nearly three-fourths the 
length of the whole body : ambulacra even with the radial lips 
or above them : Spiracles ten in number and vary from punc- 
