HERMAPHRODITE. 223 



(Herm.) Capitulum with 14 valves, including the 

 rudimentary rostrum : upper latera irregularly oval. 



Mandibles, with four or live teeth : maxillae, with the 

 edge straight, bearing numerous spines. 



Complemental Male flask-formed, with four rudi- 

 mentary valves; no mouth; cirri not prehensile; attached 

 to the occludent margin of the scutum, near the umbo. 



Great Britain, Ireland, France, Norway, Naples. Attached to horny 

 corallines, at from twenty to thirty, sometimes even to fifty fathoms in depth, 

 according to Eorbes and MacAndrew. 



HERMAPHRODITE. 



Description. — Capitulum much flattened with the apex 

 produced, of a pale brown colour, sometimes faintly 

 tinted purple, composed of 14 valves, of which the ros- 

 trum is rudimentary and barely visible externally; valves 

 thin, white, translucent, smooth, slightly marked by the 

 lines of growth, separated from each other by rather 

 wide interspaces of colourless membrane, which is thickly 

 clothed by small, articulated spines of unequal length. 

 The valves, excepting sometimes their umbones, are also 

 covered with membrane, bearing spines, placed in rows 

 parallel to the lines of growth ; the spines are particularly 

 numerous round the orifice of the sack. 



Scuta slightly convex, thrice as long as broad ; upper 

 part much acuminated; occludent margin almost straight; 

 basal margin nearly at right angles to the occludent mar- 

 gin ; the tergal margin is separated from the lateral 

 margin by an angle more or less prominent ; a slight 

 curved ridge runs from the umbo to this angle, and this 

 deserves especial notice, inasmuch as it indicates the out- 

 line which the valve assumed in its earliest growth, and 

 which is permanently retained in most of the older fossil 

 species. Along the occludent margin, there is a trace of 

 a ledge, developed in a variable degree, and which is 

 noticed only on account of the plainly visible ledge along 

 this same margin, in the allied genus Oxynaspis. The 



