40 The American Geologist. juiy, i89i 
above), founded upon, limited to, or in any specific way characterized by 
or connected with scalariform impressions. These impressions are com- 
mon to many genera but tliese genera do not for that reason become 
synonyms for Clwuico(jniptui< as defined by its author. The charac- 
ter by which Climacogmptiis is principally distinguished is the depres- 
sion of the hydrothecal mouths below the surface of the polypary. 
Passing rapidly over that portion of the memoir which deals with 
synonymy we are glad to see Stephanograptiis, (Geinitz, 18G6), noticed 
as having clear priority over both CoenograpUis (Hall, 1868 ), and Helt- 
cogroptus (Nich., 1868), as its just claims have heretofore been ignored. 
Like the other genera mentioned it was founded upon s. fjracilis. Hall 
Grnptollthus. 
We regret that Dicellograptus Hopk., has not fared better than Cltma- 
cograptus. The definition given of Didynwgraptus is "From a mostly 
short stalk (the sicula), extend in two opposite directions, sometimes 
nearer, sometimes farther from each other, Monograptus-like branches." 
Under it is justly included (and the author includes) the two genera 
Didymogrdptus and Dicellograptus which are universally, and we believe 
most justly, regarded as belonging to two exceedingly distinct families. 
But the definition seems to us entirely too comprehensive. 
Amid the wreck of genera we are glad to recognize our old friends 
Phyllograptiis and Retlolites and to meet again on the excellent plates 
which accompany this work the assemblage of forms which has become 
classic through the labors of the two pioneers of graptolithology, Geinitz 
and Barrande. 
Underslikningar ofver Siljansomradets OraptoUter by Sv. Leonh. Torn- 
qulst. (Liuids Univ. Arsskrift torn. 26.) 
Previous writings are first passed In review. From forty species in 
1881 the number has been increased by a score. 
The order of the strata is as follows: 
MEMBER. STKATCM. 
LeptEena limestone? Leptfena limestone? 
„..,..,, ( *True retiolites slate. 
Retiolites slate j ^Transition stratum. 
Rastrites slate ^Various zones of Rastrites slate. 
Kling limestone Kling limestone. 
f Red Tri nucleus slate. 
~ . ,• . J Grey limestone. 
Tnnucleus member ^-j Bu^ek Trinucleus slate. 
[ Masur limestone. 
( Bryozoa limestone. 
Chasmops limestone < Cystid limestone. 
( *Flag limestone. 
I *Upper grey Orthoceras limestone. 
I Upper red Orthoceras limestone. 
Orthoceras limestone -j Lower grey Orthoceras limestone. 
I Lower red Orthoceras limestone. 
[^*Phyllograptus slate and green limestone. 
_,,,,.. ( Oholus gravel limestone. 
Obolus limestone -j obolus conglomerate. 
*Have yielded graptoliles. 
