XCV1 



THE VOYAGE OF H.M.S. CHALLENGER. 



correlation with the powerful extension of the four subumbral funnel cavities (ci) which 

 here grow centripetally up as far as the pylorus (gy)- The coronal sinus extends corres- 

 pondingly upwards to the pylorus, and is divided into an upper and a lower part. The 

 upper coronal sinus (fig. 0, cs') lies above the four small interradial septal nodes (hi), 

 and may probably be really considered as a peripheric section of the central stomach (gc), 

 whilst the lower coronal sinus (fig. 0, cs) lies below the septal nodes and probably alone 



Fig. 0. Pericopla quudrigala (Peromedusa?, Pericolpa). 



Interradial section, (ug) Gelatinous umbrella, (a) Coronal sinus (cs') pro'ximal part, (cs 2 ) distal part, 

 (s) Genitalia. {Jen) Catliammal nodes, {go) Gastral openings, {md) Deltoid muscles, {mc) 

 Coronal muscle, {ft.) Trcniola. (gb) Niches of the basal stomach between the tamiola. {gy) 

 Pylorus, (</c) Central stomach, {gp) Palatine opening, (go) Buccal stomach (oesophagus), {am) 

 Oral margin, (oi) Sense clubs (interradial). {oa) Ampulla? at their base. (6m) Horseshoe-shaped 

 canal of the marginal lobes {la), {kl) Peronia between the two limbs of the canal {bl). {tp) 

 Tentacles (perradial). 



corresponds to the true primary coronal canal of the other Tesseronise. If this view be 

 correct, the true gastral ostia (and at the same time the four perradial pouches) are repre- 

 sented by the horizontal cleft spaces between the four nodes, whilst the vertical fissures in 

 the wall of the central stomach, which we have described as gastral ostia (fig. 0, go) must 

 be regarded as four cruciate pouches of the central stomach. It is possible, however, that 

 the upper coronal sinus (cs') has arisen from the secondary confluence of the four large 



