No.463] WORTH AMERICAN INVERTEBRATES. 439 
. Body contains only a moderate amount of parenchyma 2. 
2. Esophagus provided with large caecum extending on ene side of 
esophagus proper and ending blindly posteriorly 

Fic. pe Outlines Hi puis showing number and arrangement of ocelli. 
A , P na 

T 
latus; br, brain, cv, dv, lv, cephalic, dorsal, and latera! vessels respectively. 

B,+ 
C, A. ch 25ilis. 
. Imparispßinosus. 
2. Esophagus without ventral caecum . 3. 
3. Proboscis usually provided with only two ‘pouches ol accessory stiet 4. 
3. Proboscis provided with more than 2 pouches of accessory stylets 16. 
4. Ocelli in a single row on each side of head. 



A B C D A FK G 
Fic. 4.—Outl f central stylets and tases. 
A, A Pip abd de E, A. uentatur, 
B, A. bimaculatus. F, A. similis. 
C, A. tigrinus. G, A. impar ispinosus 
D, A. nebulosus. 
