REPORT ON THE DEEP-SEA MEDUSA. 107 



investigation, however, it shows several very remarkable and important conditions of 

 formation not to be found at the present day in the majority of Discomedusse, and which 

 may be considered extremely old peculiarities inherited from the common ancestral form 

 of the Acraspedse. In this way Natiphanta comes nearer the Tesseronise than the other 

 Ephyroniae, and connects these two sub-sections of the Acraspedae in a most interesting 

 fashion ; above all, it is remarkable in one respect, that the four important interradial 

 septal nodes or cathamma which separate the four broad perradial gastral pouches and 

 which have disappeared entirely in most Discomedusse, still exist here. The reproductive 

 glands lie in the subumbral wall of the coronal intestine below the septal nodes (much 

 further, therefore, towards the exterior than in most other Discomedusge) But in the 

 peculiar nature of the central principal intestine, and also in that of the peripheric coronal 

 intestine, we find manifold peculiarities which recall the Tesseroniaa more than the 

 Ephyronise, and which must be regarded as very ancient heirlooms from the common 

 ancestral form of the two sections. 



The axial principal intestine (" gaster principalis," figs. 2-7) appears at first sight to 

 consist, as in the other Discomedusse, of two principal sections, of the upper (aboral) 

 central stomach and the lower (oral) buccal stomach ; the former is covered by the 

 umbrella disk, and is itself flatly discoid ; the latter is more funnel-shaped, and hangs 

 freely down in the umbrella cavity. The buccal stomach is, however, constricted in the 

 middle ; this stricture probably corresponds to the palatine opening (" porta palatina," 

 gp), in which case we can probably still distinguish here all the three gastral chambers 

 of this section of Medusa?. The boundary between the two principal sections is formed 

 by the horizontal cathammal plane, in which the four septal nodes or cathamma (Jen) are 

 placed ; these may be considered the pyloric opening (" porta pylorica," gy). Other- 

 wise the three gastral chambers have an extremely simple formation. If the foregoing 

 supposition be correct, the buccal stomach or oesophagus (" proboscis ") is limited to the 

 oral half lying below the palatine opening (gp), which has the form of a truncated 

 quadrangular pyramid. The base of the latter is formed by the quadrate oral opening, 

 from whose four corners the four perradial short triangular oral lobes project (figs. 12, 14, 

 al). It only extends as far as the proximal margin of the coronal muscle ; consequently 

 the oesophagus only occupies the upper half of the umbrella cavity. Above the palatine 

 opening (gp), the stomach is again dilated in the form of a flat funnel, corresponding to 

 the true central stomach (gc). This funnel opens above immediately into the flat basal 

 stomach (gb), and appears only separated from it by the four interradial pyloric valves 

 (" vavulae pylorica?," gi). These are four flat tongue-like projections, which stand out 

 centripetally from the four septal nodes in the base of the stomach, and bear the gastral 

 filaments at their upper free end (fig. 14 ;< /) ; they completely correspond to the stronger 

 pyloric valves of many Cubomedusa? (p. 98). The ideal horizontal plane, in which 

 they lie, corresponds to the pylorus of the Tesseroniae, and therefore actually forms the 



