Davenport. — Urnatella gracilis. 



PLATE I. 



atr. 



cic. 



cl.flm. 



d. mi. 



eta. 



ex. 



ex. rgn. 



ABBREVIATIONS. 



Atrium. di. ba. 



Scar of fallenoffbud. di. sep. 



Flame cell. gm. 



Migratory cell. , mu.. 



Cuticula. nl. 



Calyx. pli- crc. 

 Regenerating calyx. vt. gran. 



Basal disk. 

 Transverse septum. 

 Bud. 



Muscle fibre. 

 Nucleus. 

 Circular folds. 

 Yolk granules. 



Fig. 1. Regenerating stalk of Urnatella, viewed as an opaque object. X 96. 

 " 2. Optical section of the same. X 96. 

 " 3. Optical section of the distal end of a stalk of Urnatella which is probably 



about to regenerate, from living animal. X 410. 

 " 4. Optical section of the proximal urn of the stalk of Urnatella. Showing 



thick cuticula and yolk granules. X 165. 

 " 5. Contents of proximal urn, obtained by crushing. Moving cilia were visible. 



Nuclei in some of the yolk granules. X 320. 

 " 6. Stock of Urnatella viewed as opaque object. Three stems arising from 



the basal disk. Buds and regenerating terminal calyces. X 36. 

 " 7. Optical section of stalk of Urnatella. X 96. 



