No. 463] WORTH AMERICAN INVERTEBRATES. 443 
angular spots on head ; ventral surface pale orange or flesh-color ; 14 
or 16 proboscidial nerves : ; A. bimaculatus Coe, A, P, C. 
18. Dark brown or purplish, with small, angular white spot on each side of 
head; ventral surface pink or flesh-color; 17 to 20 proboscidial 
nerves ; occasionally with 4 pouches of accessory stylets 
A. angulatus (Fabr.) Verrill; B, A, P, X 
19. Esophageal czcum terminates posteriorly in front of anterior ends of 
intestinal caeca ; ben parenchyma comparatively well developed ; 
ocelli few . A. rubellus Coe, S', 20-50. 
19. Esophageal caecum etin: oy far beyond anterior ends of 
intestinal caca ; mii Pr but little developed ; ocelli numer- 
ous } A. occidentalis Coe, P', 40-97. 
TETRASTEMMA. 
1. With 4 well developed ocelli 2. 
1. Ocelli fragmented or wanting ` : : é A ; ee 




B. T. quadrilineatum. 
C, T. nigrifrons. 
F, T. reticulatum. 
2. Body not especially firm, somewhat flattened 3. 
2. Body remarkably firm, cylindrical (CinsrEDIA. y B. 
3. With distinct longitudinal brown stipes on dorsal ‘surface 4. 
3. Without distinct longitudinal stripes of brown on dorsal surface. 5. 
4, Flesh-color, creamy, or grayish, with 2 deep brown longitudinal stripes 
on dorsal surface ; 5 to 10 mm. in ength . T. bilineatum Coe, S 
4. Whitish, with 4 deep brown longitudinal stripes, of lt 2 lie on lat- 
surface ; 8 to 12 mm. in len 
"€ vim T. quadrilineatum Coe, S. 
. * . 6. 
5. Blood corpuscles distinctly red 
