PLATE VIII. 



The lettering is the same in all the figures. 



a Acontia. 



b Mesenteric filaments. 



c Stomata in the septa. 

 c 1 Perioral stomata. 

 c ■ Marginal stomata. 

 rn. i 'uticle. 



d Glandular streaks of the mesen- 

 teric filaments. 



e Ciliated streaks of the mesenteric 

 filaments. 

 ek Ectoderm. 

 en Endoderm. 



g Reproductive organs. 



h Septa, rh Directive septa. 



i Oral disk. 



k Wall. 

 I Pedal disk. 

 m Muscles. 

 mm Mesodermal muscles. 

 ml Longitudinal muscles of the sept 

 mP Retractor. 

 mp Parietobasilar muscle. 

 mt Transverse muscles. 

 mr Radial muscles of the oral disl 

 and longitudinal muscles of tin 

 tentacles 

 ms Circular muscle of the wall. 

 ///<■ Mesoderm. 

 n Urtieatiug cells. 

 o Ovicells. 



p Filamental apparatus of the ovicells. 

 p 1 Process of the ovicell. 

 p 2 Apical set of epithelial cells. 



r Marginal spherules. 

 rh Directive septa. 



s (Esophagus. 

 so Openings of the (esophagus into 



the radial chambers. 

 sr (Esophageal grooves. 

 sz Lappets of the oesophagus. 



I. Tentacles and the openings homolo- 

 gous with them. 

 t 1 Principal tentacles. 

 t - Accessory tentacles. 



v Openings of the pedal disk. 



All statements given as to magnifying powers have reference to Zciss's system. 



Oc. 1. Oc. 2. 



a 1 6 10 



A 55 70 



C 95 125 



The magnifying powers amount to 



Oc. 1. Oc. 2. 



.. 195 240 



.. 410 550 



.. 470 580 



A with unscrewed front lens (unscr. A) magnifies with Oc. 1 : 30 times; with Oc. 2 : 40 times. 



D 



F 

 J 



Fig. 1. Transverse section through the wall of Phellia pectinata. D, Oc. 2. 



Fig. 2. Transverse section through the directive septa of Phellia pectinata below the 

 oesophagus. A, Oc. 2. 



Fig. 3. Part of a transverse section through the longitudinal muscular swelling 

 (retractor) of a septum of Tealia bunodiformis.. C, Oc. 2. 



Fig. 4. Longitudinal section through the wall of Tealia bunodiformis with endo- 

 derrnal saccules. A, Oc. 2. 



Fig. 5. Part of a transverse section through the oesophagus, the wall, the directive 

 septa, and the adjoining septa of Tealia bunodiformis. a 1 , Oc. 1. 



Fig. 6. Transverse section through the wall of Cereus spinosus. Fig. a, a portion 

 of the cuticule, drawn out like a tube. D, Oc. 2. 



Figs. 7, 8. Portions of the circular muscle of Tealidium cingulatum, taken at different 

 points. J, Oc. 2. 



Fig. 9. Endodermal muscles of the oral disk of Comactis flagellifera. D, Oc. 2. 



Fig. 10. Portion of a transverse section through the circular muscle of Phellia 

 pectinata. D, Oc. 1. 



