Introduction to Anwial Morphology. 105 



mis. 5. Cepheidae — with four genital pouches, and sub- 

 .genital pores ; short, complex stomatodendra, with sucking 

 mouths between the terminal twigs ; tentacles long, thin ; 

 ■eyes eight; ex.Cephea, Cotylorhiza. 6. Crambessidae — with one 

 •central, cross-shaped genital pouch over the stomach, and 

 four sub-genital pores ; arms unbranched, with no tentacles, 

 but with many rows of isolated, wrinkled, capitate, sucking 

 knobs ; four per-radial, and four inter-radial eyes ; ex. Cram- 

 bessa. 



2. Pelagiada — Discophorans with marginal ten- 

 tacles, containing processes of the anastomosing 

 somatic canals around the umbrella margin. The 

 trophosome may be fixed, but producing free gono- 

 somes ; or free, developing its sex-organs in its own 

 umbrella. The mouth is central ; the gastrovascular 

 system consists of pouch-like processes. 



There are three families : — 



I. Charybdaeidae — with no marginal canal, simple mouth- 

 pillar, and branching lateral canals. The tentacles may be four 

 ^(Charybdaea), or four bundles (Tamoya). The former genus 

 has a lenticular eye-mass (Fig. 14), and pigment spot, imbedded 

 in its pillared lithocyst, into which latter a pouch of the 

 lateral canal is prolonged. 2. Pelagiidae — with a marginal 

 •canal ; mouth-pillar, with four long, lobate (Chrysaora) or 

 leaf-like lobes around the mouth (Pelagia), or simple, four- 

 angled (Nausithoe). There are no radial branched canals, 

 and eight or twelve to twenty-four marginal tentacles (Chry- 

 saora) ; when eight they may (Nausithoe), or may not, alter- 

 nate with sense-organs. 3. Medusidae — mouth-pillar un- 

 tbranched, lobed ; stomach with or without pouches ; radial 

 •canals branched, and with a marginal canal. The marginal 

 tentacles may be very many (Aurelia, Fig. 15), or few, or 

 none ; in the latter cases there may be eight (Sthenonia), or 

 sixteen (Phacellophora), or very numerous bundles of ten- 

 tacles on the under side of the disc (Cyanea). The sto- 

 mach is four-pouched in the last genus. 



