PLATE VI. 



The lettering is the same in all the figures. 



a Acontia. 



i Mivsenteric filaments, 

 c Stoinata in tho septa, 

 c' Perioral stomata. 

 c - Marginal stomata. 

 cu. Cuticle. 



d Glandular streaks of the mesen- 

 teric fiLiments. 

 e Ciliated streaks of the mesenteric 

 filaments. 

 ek Ectoderm. 

 en Endoderm. 

 g Reproductive organs. 

 h Septa, rh Directive septa, 

 i Oral disk. 



k Wall. 

 / Pedal disk. 

 m Muscles, 

 mm Mesodermal muscles. 

 ml Lougitudiual muscles of the septa. 

 ml^ Eetractor. 

 mp Parietobasilar muscle. 

 mt Transverse muscles. 

 mr Radial muscles of the oral disk 

 and longitudinal muscles of the 

 tentacles 

 7)13 Circular muscle of the wall. 

 mc Mesoderm, 

 m Urticating cells. 

 OviceUs. 



p Fil?mental apparatus of the ovicells. 

 p'- Process of the ovicell. 

 p~ Apical set of epithelial cells. 



r Marginal spherules. 

 rli Directive sejita. 



.9 Qisophagus. 



so Openings of the ojsophagus into 

 the radial chambers. 



sr fEsophageal grooves. 



s: Lappets of the cesophagus. 

 t Teutacles and the openings homolo- 

 gous with them. 



t ' Principal tentacles. 



I - Accessory tentacles. 



V Openings of the pedal disk. 



All statements given as to magnifying powers have reference to Zeiss s system 



Oc. 1. Oc. 2. 

 ai ... 6 10 D 



A ::: ::: ... 55 70 f 



C 95 125 J 



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



The magnifying powers amount to 



Oc. 1. Oc. 2. 



... 19:. 240 



410 550 



470 580 



Fig. 1. 

 Fig. 2. 

 Fig. 3. 

 Fig. 4. 

 Fig. 5. 

 Fig. 6. 



Transverse sections through different forms of the circuUar muscle. 



Circukr muscle of Cereus spinosus. a\ Oc. 1. 



Tecdidium cingidatum. 0, Oc. 2. 

 Pohjsiphonia tuherosa. a\ Oc. 2. 

 Tealia hunodiformis. C, Oc. 2. 

 Phellia pectinata. a', Oc. 2. 

 Comactisflcujellifera. C, Oc. 2. 



