OF AMERICA NORTH OF MEXICO. 
313 
while Dislenia, although strongly resembling Cerasphorus, put among Leplurce. 
Again, there are many true Cerambyci, (e. g. Ilenopterus,) which have the head 
elongate and porrected : Necydalis likewise has the head suddenly contracted behind 
precisely like Toxotus, while the front is deflected and the palpi filiform; so that it 
becomes difficult to determine whether the genus belongs to the Leptum, Ceramby ci 
or Lamice. 
So fallacious are the received characters, that a genuine Saperda-ioxm. with 
abbreviated elytra, has been described both by Newman and Haldeman as a 
Molorckus, {Thia, Nm., Tessaropa, Hald.) and another genus {Encylops, Nm.) allied 
to Necydalis, has been placed near Toxotus. A new genus from Georgia has a 
remarkable resemblance to Dorcadioti, whilst the head is prolonged behind the eyes, 
and its true affinity is with the gibbous Clyti. It is thus plainly seen that these 
divisions so distinct in nature, have not yet any natural distinctions in our systems. 
Dr. Zimmerman has recently recognized the importance of a character heretofore 
neglected, and through his kindness I am enabled to make use of it in the present 
essay. He finds that in all Laniia-ioxm&, the anterior tibi® have an oblique .sulcus 
internally, which in many cases becomes so deep as to form an emargination, such as 
IS observed in most Carabica. This character, with a single exception, is wanting in 
all other Longicornia. Making use of it and at the same time suppressing the 
primary group Lepturce, as not possessing sufficiently distinct characters, we obtain 
three great divisions which embrace all Longicornia. 
1. LAMI^. 
2. CERAMBYCI. 
' 3. PRIONI. 
Tibice antic® intus oblique 
sulcat®. 
Palpi semper filiformes. 
Anlennce verticales. 
Thorax immarginatus. 
Coxa: antic® globos®. 
Tibice intus non sulcat®. 
{Michthysomate excepto.) 
Palpi s®pissime compress!. 
Thorax immarginatus. 
Tibice intus non sulcat®. 
Palpi compressi. 
Aniennce frontales. 
Coxa: antic® valdo trans- 
vers®. 
The Cerambyci may again be divided into three groups according to the form of 
the anterior cox® and tibi®. 
1. LEPTURID^. 
Tibiae filiformes. 
Coxae antic® conic®. 
2. CERAMBYCIDtE. 
Tibiae filiformes. 
Coxae antic® vel globos® vel 
subtransvers®. 
3. SPONDYLID^. 
Tibiae antic® compress®. 
Coxae antic® subtransvers®. 
