PLATE XL 



Figs. 1-7. Culeolus recumbens, Herdnian. 



Figs. 8-9. Culeolus perlatus, Suhm. 



Figs. 10-14. Culeolus perlucidus, Herdman. 



Fig. 1. Culeolus recumbens, a specimen seen from the right side ; natural size. 



Fig. 2. Another specimen, from the left side ; natural size. 



Fig. 3. The branchial aperture of fig. 1 ; natural size. 



Fig. 4. The atrial aperture of fig. 1 ; natural size. 



Fig. 5. Part of the branchial sac, from the inside ; magnified (Hartn., obj. 4). 



Fig. 6. The dorsal part of the anterior end of the branchial sac, showing the peri- 

 pharyngeal bands, the nerve ganglion, and the dorsal tubercle ; magnified 

 (Hartn., obj. 4). 



Fig. 7. Dissection, showing the alimentary canal and the genitalia of both sides ; slightly 

 enlarged. 



Fig. 8. Culeolus perlatus, from the left side ; natural size. 



Fig. 9. Part of the branchial sac, from the inside, showing a fold (br.f.) ; magnified 

 (Hartn., obj. 4). 



Fig. 10. Culeolus perlucidus, from the right side ; natural size. 



Fig. 11. Part of the branchial sac, from the inside, showing two of the simple folds 

 (br.f.); magnified (Hartn., obj. 4). 



Fig. 12. The dorsal part of the anterior end of the branchial sac, showing the peri- 

 tubercular area, the dorsal tubercle, the peripharyngeal bands, and the nerve 

 ganglion; magnified (Hartn., obj. 4). 



Fig. 13. Outline of the alimentary canal and the genital glands ; slightly enlarged. 



Fig. 14. Part of one of the genital masses cut to show the hollow interior and the ducts ; 

 somewhat enlarged. 



