60 THE VOYAGE OF H.M.S. CHALLENGER. 



cal or quadrangularly pyramidal shape, and opens with the truncated aboral end into the 

 peduncle stomach by the pyloric opening (" pylorus," gy) and with the cpuadratic, strongly 

 constricted oral basis into the buccal stomach by the palatine opening (" palatum," gp). 

 Four perradial clefts, the gastral openings (" ostia gastralia," figs. 2, 3,gp ; fig. 21, go) lead 

 from the central stomach into the four radial pouches. As the four, conical interradial 

 funnel cavities (ii) already described project arch-like between the four gastral openings 

 into the central stomach, the formation of the latter becomes rather complicated. Both 

 margins of the cleft-shaped gastral openings are edged nearly their whole length by a row 

 of fine gastral filaments (fig. 21,/) ; these are only wanting on the lower (oral) fourth of 

 the gastral openings where their margin forms the cartilaginous-like thickened groove of 

 the palate (fig. 21, gs). The rows of filaments or phacelli run above to the point of the 

 funnel cavities, but do not pass on to the solid tseniola. In comparison with other 

 Lucernaridse, and with the considerable size of our species, its filaments appear slightly 

 developed, very fine and rather short ; they are limited here to the lateral margin of the 

 gastral openings, whilst in other species they often extend distally far on to the lateral 

 margins of the genitalia, or proximally on the basal tseniola. Like the filaments, the oeso- 

 phagus or " buccal stomach " seems only slightly developed in Lucemaria bathyphila 

 (proboscis, figs. 2-4, ga). It forms a low, fleshy, membraneous border, quadrate in outline, 

 which only projects sbghtly from the palatine opening into the umbrella cavity. The 

 thickened glandular margins of the oral opening are only slightly frilled (fig. 9). The 

 four perradial angles of the oesophagus pass at the palatine opening, into the four sub- 

 urnbral mesogonial folds (ivz). 



The peripheric coronal intestine (" gaster coronaris "), which only communicates by the 

 four perradial gastral openings with the central stomach, in Lucemaria bathyphila is 

 formed (owing to the slight development of the eight arms) almost exclusively by the 

 four voluminous radial pouches (" bursse radiales," bp) which Clark termed " quadrant 

 chambers," Keferstein " broad pouch-shaped radial vessels," Taschenberg " radial canals," 

 KJing "radial chambers," and Hertwig "radial chambers or radial pouches." These 

 present four flat pouch-like hollow spaces extending between the umbrella and subum- 

 brella to the umbrella margin. They are only divided by four interradial " septal 

 selvages," or "lines of fusion," linear septa in w T hich the umbrella is fused with the 

 subumbrella (" septa cathammalia," ks). As this fusion does not, however, extend as far 

 as the umbrella margin, the four pouches communicate there below the distal end of the 

 septa, by four interradial circular openings, so that a circular communication, a sort of 

 "circular canal," is formed on the umbrella margin (fig. 12, cc). The proximal half of 

 the four radial pouches opens by the gastral openings into the central stomach ; whilst 

 eight lobe pouches or " arm pouches " (" bursas lobares ") run from its distal margin into 

 the eight arms. The end of each lobe pouch again sends out a tentacle canal into each 

 tentacle (figs. 15-16, ct). As the eight arms or marginal lobes in our species project onlv 



