SECTION L: 
SECTION M: 
1 
2. Single, medioventral, 
3. Single, mediocentral, 
4. Single, on left side 
5. Absent 
6. 
Ts 
tsi 
Sie 
Ors 
SECTION N: 
« Medial 
SUBJECTIVE EVALUATIONS OF 
SHEATH, SHAPE OF ARCH) 
Narrow/wide "y" 
Wide/wide "vy" 
Absent 
Wide/narrow "Vv" 
Medium/flexed "yv" 
Wide/wide "Uy" 
Medium/wide "U" 
Narrow/"U"-shaped 
Wide inverted "U" 
Dual and lateral 
on belly or chest 
near vent tube 
LOWER JAW SHEATH CONFIGURATIONS 
(WIDTH OF 
CONFIGURATIONS OF SPIRACLE(S) 
(amphigyrinid) 
Medium/wide "Vv" 
Narrow/narrow "Vv" 
Medium/narrow "vy" 
Narrow/flexed "vy" 
Wide/flexed "vy" 
Narrow/wide "U" 
Wide/"U"-shaped 
Medium/"U"-shaped 
Wide/broken 
(mediogyrinid) 
(mediogyrinid) 
(laevogyrinid or sinistral) 
Single, low on left side but not medioventral (paragyrinid) 
CONFIGURATIONS OF VENT TUBE 
Dextral 
