VI SUCTORIA = TENTACULIFERA I 59 



Acineta, Ehrb. (Fig. 61, 2) ; Amoehophrya, Koppen ; Choanofhrya, 

 Hartog (Fig. 62); Dendrocometes, St. (Fig. 61, 4); Bendrosoma, 

 Ehrb. (Fig. 61, 9) ; Endosphaera, Engelin. ; Ephelota, Str. Wright 

 (Fig. 61, f), 8) ; Hypocoma, Gruber ; Ophryodendron, CI. and L. 

 (Fig. 61, 7); Podophrya, Ehrb. (Fig. 61, 1); Bhyncheta, Zenker 

 (Fig. 61, 3); Sphaerophrya, CI. and L. (Fig. 61, 6), Sudorella, 

 Frenzel ; Tokophrya^ Biitschli. 



This group, despite a superficial resemblance to the Heliozoa, 

 show a close affinity to the Ciliata ; the nuclear apparatus is 

 usually double though a micronucleus is not always seen ; the 

 young are always ciliated, and the mode of conjugation is 

 identical in all cases hitherto studied. Most of the genera are 

 attached by a chitinous stalk (Fig. 61), continued in Acineta 

 into a cup or " theca " surrounding the cell. The pellicle is firm, 

 often minutely shagreened or " milled " in optical section by fine 

 radial processes, whether superficial rods or the expression of 

 the meeting edges of radial alveoli is as yet uncertain. The 

 pellicle closely invests the ectosarc, is continued down into 

 a tubular sheath, from the base of which the tentacle rises, and 

 upwards to invest the tentacle, and is even prolonged into its 

 cavity in Clioanopkrya, the only genus where the tentacles are 

 large enough for satisfactory demonstration. These organs may 

 be one or more, and vary greatly in character. They may be (1) 

 pointed for prehension, puncture, and suction {Ei^helota, Fig. 

 61, 5); (2) nearly cylindrical, with a slightly "flared" truncate 

 apex {Podophrya, Fig. 61, i«) ; (3) filiform with a terminal knob ; 

 (4) "capitate" {Acineta, Y\g. 61, 2); (5) bluntly truncate and 

 capable of opening into a wide funnel for the suction of food ^ 

 {Choanoijhrya, Fig. 62; Rhyncheta, Fig. 61,3). Their move- 

 ments, too, are varied, including retraction and protrusion, 

 and a degree of flexion which reaches a maximum in Bhyn- 

 cheta (Fig. 61, 3), whose tentacle is as freely motile as an 

 elephant's trunk might be supposed to be were it as slender in 

 proportion to its length. They are continued into the body, 

 and in Choanojfhrya may extend right across it. In Podoplirya 

 trold the pellicle rises into a conical tube about the base of the 

 tentacle, which is retracted through it completely with the prey 

 in deglutition. In Dendrocometes, Dendrosoma, and Ophryo- 

 dendron (Fig. 61, 4, 9, 7), the tentacles arise from outgrowths of 



^ In this case the debris of the live prey torn up by the Cyclops on vhich 

 they live. 



