in (1. Naturgesch. d. nied. Thiere währ. d. Jahre 1876—1879. 561 



First under arm-plate rather large and bearing some of the scales 

 of the second pair of mouth-tentacles. Upper arm-plates covering 

 the whole width of arm. Sraall smooth arra-spincs, arranged along 

 oiiter edge of side arm-plate. Two large long genital openings in 

 each interbracliial space. (Hat manche Aehnlichkeit mit Ophio- 

 glypha.) 



Ophiotrochus Lym. Disk flat and round, covered with thin 

 more or less granulated scales and nacked radial shields. Arms 

 slender, tubulär, each Joint constricted at its base; side arm-plates 

 meeting widely above and below; upper arm-plates rudimentary. 

 Scale of second pair of mouth-tentacles lying between side mouth- 

 shield and outer mouth-papillae. There are teeth and mouth-pa- 

 pillae; no tooth-papillae. Sraooth arm-spines on outer edges of side 

 arm-plates. 



Ophiophyllum Lym. Disk extremely thin and flat, covered 

 with scales and large radial shields and bordered by a row of plates, 

 which are movable and attached by their inner margins. Mouth- 

 papillae arranged in a close row; no tooth-papillae; teeth. Arm-spines 

 thin and broad, standing on outer edge of side arm-plates. Two 

 genital openings in each interbrachial space. (Ein ziemlich isolirt 

 stehendes Genus, dessen Randplatten einigermassen an die platten 

 Stacheln von Podophora erinnern.) 



Ophiobyrsa Lym. Entire animal clothed in a thick skin, 

 which hides the underlying plates and is beset on the disk with 

 spines. Arm nearly cylindrical. Side arm-plates projecting as short 

 flap-like spine-ridges, which bear slightly rough spines on their outer 

 edge. Tentacles large and simple. Few or no mouth-papillae, but 

 at apex of mouth-angle the teeth and tooth-papillae are represented 

 by a clump of little spines. Two large genital openings in each 

 interbrachial space. 



Ophiochiton Lym. Disk covered with fine imbricated scales 

 and small radial shields. Numerous sharp mouth-papillae with teeth, 

 but no tooth-papillae. Upper and under arm-plates about as broad 

 as long and separatiug the side arm-plates, which project slightly 

 and are rather small. Under plates furnished with a median longi- 

 tudinal ridge. Arm-spines slender and smooth, arranged on the 

 sides of the side arm-plates, near the outer edge. Two long genital 

 openings in each interbrachial space. (Von Ophiarachnia durch die 

 Bedeckung der Scheibe verschieden.) 



Ophiopyrenliym. Disk granulated. Teeth; no tooth-papillae; 

 numerous mouth-papillae arranged in a close line, Mouth-framea 

 long and conspicuous. Side mouth-shields small and widely sepa- 

 rated by the mouth-shield. Under arm-plates divided in two parts 

 by a crease or Joint. Arm-spines standing on outer edge of side 

 arm-plates. Two genital openings in each interbrachial späce. 



