PEELIMINAEY CLASSIFICATION OF SCOLYTOIUEA. 



205 



represents a high stage of progress, and consequently they are more 

 characteristic of the species. 



The form of the egg gallery of any species consists of one or more 

 of three primary elements in relation to the substance and its fiber 

 in which the gallery is made, as follows: (1) The longitudinal gallery, 

 (2) the transverse gallery, and (3) the broad, irregular chamber. 



Types and Subtypes of Egg Galleries. 



The various modifications and combinations of the three primary 

 elements seem to represent 8 general types or groups, which are 

 designated by numbers, and 32 more specific subtypes or forms, 

 which are designated by letters, as follows (see fig. 112) : 



Group 1. — The simple or generalized type, (a) Simple, longitudinal; (6) simple, 

 transverse; (c) simple cavities; (d) various combinations of a and b, with lateral 

 . branches. 



Group 2. — The simple, irregular type branching from an irregular central or basal 

 chamber, (a) Long, longitudinal, branching; (h) short, sublongitudinal, branching; 

 (c) short, transverse, branching; {d) various combinations of h and c. 



Group 3. — Ambrosia galleries. Division I, without lateral larval chavibers. (a) Sim- 

 ple, longitudinal, single or branching; (6) long, transverse, branching; (c) short. 



Fig. 112. — Classification of galleries of Scolytoidea. (Original.) 



transverse, branched, dilated. Division II, tvith lateral larval chambers, (d) Double, 

 transverse, branching; 



Group 4- — The specialized, intermediate, short type, branching from a regular cen- 

 tral nuptial chamber, (a) Simple to complex, transverse; (6) simple to complex, 

 sublongitudinal; (c) intermediate combinations of a and 6; (rf) complex, symmetrical 

 combinations of a and b. 



Group 5. — The specialized, intermediate, long, longitudinal type, branching from a 

 regular central chamber, (a) Simple, irregular types with few branches; (6) special- 

 ized, many-branched types; (c) specialized, with few branches, usually three; {d) 

 specialized, double, longitudinal. 



Group 6. — The specialized, short, transverse type, (a) Simple, irregular, single or 

 double, transverse or sub trans verse, and sometimes branching; (6) intermediate, 

 regular, double, transverse or sub transverse ; (c) specialized, regular, double or single, 

 transverse, with or without lateral entrance chamber. 



Group 7. — The specialized, short, double, longitudinal type, (a) Irregular, 

 branched ( Micracis) type; (6) irregular, without branches, but with lateral entrance 

 chambers; (c) intermediate, more specialized, with or without lateral entrance chamb- 

 ers; (d) highly specialized, without lateral entrance chambers. 



Group 8. — The specialized long or short, single, longitudinal type, (a) Long, 

 irregular, winding, sometimes with lateral branches, with or without lateral entrance 

 chambers at base; (6) short, irregular, without branches, but with lateral entrance 

 59026°— 15 4 



