446 POLYPI. CILIATI. 



B. squamula, Lam. Shell univalve, orbicular ; apex truncated, four- 

 toothed, base entire. Lam. ii. 34. 



** Tail simple and naked. 



B. passus, Lam. Capsular shell cylindrical, the fore part with 

 two pendulous cirri, and one caudal seta. Inhabits salt marshes. 

 Lam. ii. 35. 



*** Tail terminated in two points or seta?. 



B. lamellarisy Lam. Univalve ; shell produced ; apex entire ; base 

 three-horned; tail with two hairs. Inhabits marshes. Lam. ii. 35. 



B. ovalis, Lam. Bivalve ; shell depressed ; apex emarginate, base 

 cleft ; tail with double cirrus. Inhabits marshes among Confer- 

 vae. Lam. ii. 36. 



Gen. 6. FOLLICULTNA, Lam. 



Body contractile, oblong, inclosed in a transparent sheath ; 

 mouth terminal, large, with ciliated and rotatory organs. 



F. ampulla, Lam. (Vorticella, Mull.) Follicle swelling, pellucid; 

 head bilobed. Inhabits sea water. Lam. ii. 30. 



SECTION II. VIBRATILES. 

 Ciliae near the mouth moving in interrupted vibrations. 



The minute animals which form this section are the most imperfect of the polypi, 

 and seem to lead to the appendiculated Infusoria. They are chiefly distinguished 

 from these by their having a mouth. They are gelatinous and transparent. 



Gen. 7. VAGINICOLA, Lam. Trichoda, Mull. 



Body very small, oval or oblong, ciliated anteriorly, furnished 

 with a tail, and inclosed in a transverse sheath, not fixed. 



V. inquilina, Lam. Follicle cylindrical, hyaline ; a twisted pedi- 

 cle beyond the follicle. Inhabits sea water. Lam. ii. 27. 



V. innata, Lam. Follicle cylindrical ; tail exserted beyond the 

 follicle. Inhabits sea water Lam. ii. 27- 



Gen. 8. TRICHOCERCA, Lam. 



Body very small, oval or oblong, truncated anteriorly ; mouth 

 retractile, subciliated, tail forked, sometimes articulated. 

 * Tail not articulated. 



T. vermicularis, Lam. Cylindrical, annulated, with an exsertile 

 proboscis; spines of the tail double. Inhabits rivulets. Lam. ii.25. 



** Tail long, articulated. 



T. longicauda, Lam. Cylindrical, truncated and crinited before ; 

 tail long, biarticulated, with two setae. Marshes. Lam. ii. 26. 



Gen. 9. RATTULUS, Lam. 



Body very small, oblong, truncated or obtuse anteriorly ; mouth 

 distinct ; tail very simple. 



R. carinatus, Lam. Oblong, carinated, crinited before ; tail seti- 

 form, very long. Inhabits water of ditches. Lam. ii. 24. 



