28 (27) Each claw has more than two exposed points 

 28 {27) Each claw has one or two exposed points ... 



29 

 30 



29 (28) Body flattened dorsovenlrally; cephalic 

 appendages reduced; ectocommensal 

 Tetrakentron synaptae 



29 {28) Body cylindrical 



30 



30 (29) Each claw has three exposed points 31 



30 (25) Each claw has four exposed points Bathyechiniscus tetronyx 



13 



