DESCRIl'TION OF THE PLATES. 127 



Fig. 65 (200 diam.). A group of digitiform bodies (digituli) pendent from the eircuinoral floor. 

 One of tbeni is remarkable for its triple forking. 



Fig. 6G (5 diam.). The peduncle and a part cjf the umbella near a paftition (4-), including a 

 marginal body (colletocy.stophoro) (a); chiefly to display the distinctness, from an exterior view, of 

 the canals (t'), and the filmy caudal .sheath (t')- The deep furrow (t") lies over the muscular cord 

 which extends forward into the partition (4.^ 4'^) of the umbella. 



PLATE VII. Figures 67 to 84. 



Figs. Gt to 73 {175 diam.). A progressive series of developments of the genital sac, seen from 

 different points of view. Fig. 67. View from within the umbella. Fig. 68, same -ds Jig. 67, but seen 

 from the end opposite the entrance (s*) of the sac, the outer wall (i) overlying the initiatory double 

 folds (j-) of the inner, or ovigerous layer. (Compare Jig. 74, and adult sac.) Fig.s. 60 and 70, face 

 and profile of the same sac seen from within the umbella. Figs. 71 and 72 face and end views of the 

 same sac, the third in the series, seen from the exterior, through the circumoral floor. Fig. 73, the 

 fourth and last of the series, seen from without, as in the last; 



Fig. 74 (350 diam.). One of the smaller genital sacs, of an adult female, sectional profile, pendent 

 from the circumoral floor. The aperture (.s^), surrounded by large vibratile cilia, leads into a central 

 chamber (s') surrounded by ovigerous follicles. 



Fig. 75 (350 diam.). View from opposite the entrance (s") of a male genital sac. The follicles 

 (s-) converge toward and open into the central chamber (s'). 



Fig. 76 (350 diam.). The same as Jig. 75, seen through the circumoral floor, from a different 

 point of view. 



Fig. 77 (350 diam.). Empty female genital sac, chiefly to show the manner in which the follicles 

 (.s') open into the central chamber (s'). 



Fig. 78 (^350 diam.). An egg-follicle to illustrate the histological character of the ovigerous layer 

 (i") (internal oophragma), and the position of the eggs (vi). 



Fig. 79 (350 diam.). An empty egg-follicle dotted all over with the torn fragments of the fibrils 

 of the chondromyoplas (sec Jig. 77, 6'). 



Fig. 80 (200 diam.). Singular attitude of a digitulus (ij), its sides folded together to form a sac 

 with a broad mouth (ijs), imitating a genital sac (s'). 



Fig. 81. An anchor (colletocystophore) of a very young individual (Jig. 84 nat. size), and a por- 

 tion of the umbellar margin. The edge of the muscular layer (opsomyoplax) (k') is seen passing 

 obliquely from the front to the distal side. (See the dotted line k\ k', in Jigs. 82 and 83.) 



Fig. 82 (175 diam.). A combined outline and sectional view from the distal side of a young 

 anchor (from Jig. 84). The nematocystophore (a') in the distance. The dotted line (&•) indicates 

 the course of the edge of the opsomyoplax (k') as it crosses the distal side of the base of this organ. 

 The distal end of a partition (4-) is seen through the thick mass of the aboral side of the umbella. 

 The arrow lies in the intercameral passage-way. (See ■^',fig. 83.) 



Fig. 83. Profile section of the same as fig. 82, with a part of the umbella. The dotted line (^■i) is 

 the same as \n fig. 82, continued onward to the circumoral floor, where it becomes a part of the true 

 umbellar opsomyoplax (m*). In the anchor it is marked ml 



PLATE VIII. Figures 85 to 93. 



Fig. 85 (750 diam.). Portion of the opsophragnia (/<) and the underlying opsomyoplax (m) of 

 the circumoral floor, in profile. 



Fig. 86. Face-view of the cells of fig. 85. 



Fig. 87 (750 diam.). Face-view of the cells of the ectophragma of the aboral side of the umbella, 

 remarkable for the accumulation of pigment granules (d') about the nucleus. 



Fig. 88 (750 diam.). Profile section of the outer wall of the globose tip (nematocystophore) of a 

 young tentacle, with the imbedded nematocysts (I the larger and l' the smaller). 



