PLATE II. 



The lettering is the same in all the figures. 



cu Cuticula. 

 ec Ectoderm. 

 en Endoderm. 



g Generative organs. 



h Mesenteries. 

 im Intermediary layer. 

 ?/t Muscle-fibres. 



me Mesoglcea. 



ms 1 Upper circular muscle. 



m< ! Lower circular muscle. 



o Ova. 



r Marginal spherules. 

 sr Siphonoglyphe (oesophageal groove V 



t Tentacles. 



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



Fig. 1. Portion of the circular muscle of Hormathia delicatula. D, Oc. 2, somewhat 

 diminished. 



Fig. 2. llyanthopsis longiftlis ; musculature of the oral disc. 1 / 1S , Oc. 1. 



Fig. 3. Hormathia delicatula ; musculature of the oral disc. D, Oc. 2. 



Fig. 4. Circular muscle and marginal spherules of Liponema multiporum. A, Oc. 1. 



Fig. 5. Muscle-pennon of Halcampa Tcerguelensis. A, Oc. 2. 



Fig. 6. Dysactis crassicornis ; transverse section through a tentacle, a 3 , Oc. 2. 



Fig. 7. Portion of the tentacle represented in fig. 6, more strongly magnified. 

 A, Oc. 1. 



Fig. 8. Phellia spinifera ; transverse section through the musculature of the oral 

 disc. E, Oc. 2. 



Fig. 9. The same. 



