255 
stand in communication with the endoderm. I cannot confirm their 
nature, but it is possible that they are caused by a parasite. The 
ectoderm of the tentacles is high and contains rather numerous 
nematocysts 12—ISXabout 1 — 1 , 5 ,« and spirocysts 13 x 1—26 x 
2 —2,5 The longitudinal muscles of the tentacles and radial 
muscles of the oral disc are ectodermal, somewhat stronger in 
the tentacles than in the disc. The ectoderm of the actinopharynx 
is rather high and contains nematocysts 17—22 x about 2,5 (x, broader 
in the basal end and with visible basal part to the spiral thread. 
The longitudinal folds in the actinopharynx are supported by’meso- 
Fig. 47. Cricophorus nutri.v. Transverse section of about a sixth of the body 
in the actinopharynx-region. 
gloeal ridges. The cilia of the siphonoglyphes are considerably longer 
than in the other part of the actinopharynx. 
The mesenteries are hexamerously arranged in four or five cycles 
(textfig. 47). In smaller specimens there are probably not more than 
four, in larger specimens five. The last cycle, consisting of very weak 
mesenteries, is present only in the undermost part of the body and 
not provided with filaments and acontia. Only 6 pairs are perfect, 
of which two directives. The mesenteries of the second order reach 
however almost to the actinopharynx. Stuckey States “that there 
are 24 pairs, every second pair is perfect. “ He has thus neither ob- 
served the fourth cycle in smaller specimens nor the fifth in larger ones 
in the undermost part of the body, and his statement of 12 perfect 
pairs is incorrect. The mesenteries are rather weak, their longitudi¬ 
nal muscles are extended over the greater part of one side of the 
