Plate 18. 



All figures are of Pegantha martagon. 

 Fig. 1. Side view of mature specimen 20 mm. in diameter. 

 Fig. 2. Oral view of same individual. 



Fig. 3. Portion of bell margin, with otocysts (otc) and otoporpae (op). X 20. 

 Fig. 4. Two marginal lappets of a small specimen, 5 mm. in diameter, showing one sm 



tentacle more recently formed than the other two; (v) velum. 

 Fig 5. Oral view of portion of lower gastric wall of a young specimen, 12 mm. in diametc 



showing an early stage in the growth of the gonads (go), which are still siinj 



globular swellings ; (c.per) peronial canal. 

 Fig. 6. Four adjacent gonads (go) of a mature specimen, showing slight secouda 



lobing; (c.per) peronial canal. X 6. 

 Fig. 7. Otocyst and otoporpa ; (ol) otolith ; (ec) ectoderm, and (en) endoderm of otocys 



(op) otoporpa, bounded by cap-like cells ; (n) nematocyst. From a specim 



stained in borax-carmine. Bristles were seen in life, but are destroyed 



preservation, x 300. 

 Fig. 8. Somewhat diagrammatic cross-section through marginal zone in radius of a gona 



to show the gelatinous genital prominence (g.pn) which supports the centi 



region of each gonad (go) ; (c.c) circular canal. Fr.om a dissection. 



