144 REPORT OF NEW JERSEY STATE MUSEUM. 



Leidy, Proc. Acad. Nat. Sci. Phila., 1890, p. 281. Beach Haven, New 



Jersey (on Pennella Hlosa, itself on Mola mola). 



M. J. Rathbun, Occas. Papers Boston Soc. N. Hist., VH, 1905, p. 85. 



On bottom of vessels and on large sluggish fishes (New England). 

 Conchoderma virgatum Pilsbry, Bull. U. S. Nat. Mus., No. 60, 1907, p. 99, PI. 

 9, fig. I. Albatross Station 2713 (on Neptunus sayi). 



Description. — Capitulum flattened, gradually blends into pe- 

 duncle, summit square, rarely obtusely pointed. Membrane thin. 

 Valves thin, small, variable, always remote and imbedded in 

 membrane. Scuta trilobed, formed of an upper and lower lobe 

 (latter usually widest) joined into straight flat disc, with third 

 lobe projecting out from middle of outer edge and usually bend- 

 ing slightly inward. Form of lateral lobes variable from 

 rounded oblong to equilateral triangle. Terga shape very vari- 

 able, at nearly right angles to scuta. Upper ends of terga 

 imbedded in membrane, projecting freely like little horns about 

 one-third their length. Free projecting portion generally curled 

 inwards and carinal portion more or less outwards. Whole 

 valve generally of nearly equal width, carinal part very little 

 wider. Valve deeply concave internally, with both points gen- 

 erally blunt and rounded. Terga generally about two-thirds 

 length of scuta, rarely only half, and usually separated from 

 apices of scuta by about once their own length, rarely by twice. 

 Terga usually shorter than carina, sometimes very little longer, 

 and distant by third or fourth their own length from apex of 

 carina, rarely by their entire length. Carina lie nearly parallel 

 to scuta, concave within, very slightly bowed, of nearly same 

 width throughout, but with lower third beneath umbo generally 

 slightly wider than upper part. Carina length varies, usually 

 longer than scuta or terga. Upper and lower points of carina 

 rounded, rarely both ends acuminate. 



Peduncle flattened, gradually widens as it joins capitulum, to 

 which, generally about equal or a little longer in length. 

 Filamentary appendages six each side, one below basal articula- 

 tion of first cirrus longest and placed on hind edge of a swelling. 

 Second filamentary appendage little lower in side of prosoma, 

 short and thick. Third on hind edge of pedicel of first cirrus 

 above basal articulation, and fourth, fifth and sixth in similar 



