Prof. F. M'Coy on some new Protosoic Annulata. 395 



Genus Crossopodia (M'Coy), n. g. 



Etym. Kpocr<To<i, fimbria ; 'rrov^^pes. 



Gen. Char. Body long, moderately slender, of excessively short, 

 numerous, wide segments, from which arise very long, delicate, 

 crowded cirrhi, forming a broad dense fringe on each side, com- 

 pletely concealing the feet (at least five or six times longer 

 than a segment of the body, or interval between one cirrhus 

 and another). 



These beautiful worms are easily distinguished from their pro- 

 tozoic companions, the Net-eites and Myrianites, by the excessive 

 shortness of the joints of the body, as indicated by the very 

 crowded cirrhi (only one of which comes from the dorsal aspect 

 on each side of any given segment) and by the broad, close, 

 fringe-like development of these latter, concealing the lobes of 

 the feet, so conspicuous in the two genera named. 



Crossopodia lata (M'Coy). 



Sp. Char. Length unknown (upwards of 1 yard) ; width 9 lines, 

 width of body 3 lines, length of cirrhi 3 lines ; articulation of 

 body and number of cirrhi indistinct, but apparently three in a 

 space of 1 line. 



Prof. Sedgwick infonns me, that the portion of this remarkable 

 worm which he saw in the rock, and of which the specimen de- 

 scribed is a part, measured a yard in length, without signs of 

 tapering or alteration of character, thus agreeing in proportion 

 with its living allies. Its great width easily distinguishes it from 

 the older C. Scotica (M'Coy), and it has no resemblance to any 

 other fossils I know of. The piece described is about 4 inches 

 long, and is gently flexuous. 



Tilestone (Upper Ludlow) of Storm Hill, Llandeilo. 



{Col. University of Cambridge.) 



Crossopodia Scotica {M.'Coy). .i,,, 



Sp. Char. Length unknown (upwards of 3 feet), width nearly 3 

 lines, width of body (and trail on the surface of the beds) one-, 

 third of a line ; cii'rhi very fine, close^ delicate, about five in the 

 space of 1 line. 



This interesting worm is closely allied to the so-called Nereitess 

 Loomisii of Prof. Emmons's ' Memoir on the Taconic System,f> 

 t. 3. f. 3, from the taconic slates of Waterville, Maine. The 

 American species certainly belongs to our new genus Crossopodia, 

 but, if correctly drawn, has much thicker and fewer feet. The 

 narrow deep trail of the middle part of the body on the upper 

 siu'face of the planes of deposition of the slate, and the narrow 



