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 otoeysts (otc) and otoporpae (op), x 20. 

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



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 diameter, 



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



globular swellings ; (c.per) peronial canal. 

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



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

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



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



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



preservation, x 300. 

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



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



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



