130 BRITISH PALALOZOIC FOSSILS. [AnnuLata, 
MyYRIANITES TENUIS (M‘Coy). Pl. 1. D. fig. 13. 
Ref.—M ‘Coy, Ann. Nat. Hist. 2nd Series, Vol. VIT. 
Sp. Ch.—Usually coiled in numerous, small, very irregular, undulations; diameter of body about one- 
third of a line. 
This little worm is easily distinguished from the M7. Macleayi (Murch.) by its very slender propor- 
tions, agreeing more nearly in this respect with the MZ. Murchisoni of Prof. Emmon’s “Taconic Slate.” I 
think it was about a foot long, from following, as well as I could, the convolutions of three individuals. 
I have only in one part seen traces of the cirri, which have the same general proportions as in the 
M. Macleayi (Murch.) 
Position and Locality——Not uncommon in a particular layer of the fine olive slate of Greiston, on the 
Tweed, near Inverleithen. 
Explanation of Figure—P\. 1. D. fig. 13. From the slate of Greiston, on the Tweed, natural size. 
Genus. CROSSOPODIA (M°Coy). 
Ref—MCoy, Ann. Nat. Hist. 2nd Series, Vol. VIT. 
Etym.—Kpocods, fimbria; rods, pes. 
Gen. Char.—Body long, moderately slender, of excessively short, numerous, wide segments, from which 
arise very long, delicate, crowded cirri, forming a broad dense fringe on each side, completely concealing 
the feet (at least five or six times longer than a segment of the body, or interval between one cirrus and 
another). 
These beautiful worms are easily distinguished from their Protozoic companions, the Nereites and My- 
rianites, by the excessive shortness of the joints of the body, as indicated by the very crowded cirri (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. 
Crossopopia LATA (M°Coy). Pl. 1. D. fig. 14. 
Ref.—M Coy, Ann. Nat. Hist. 2nd Series, Vol. VII. 
Sp. Oh.—Length unknown (upwards of one yard); width nine lines, width of body three lines, length 
of cirri three lines; articulation of body and number of cirri indistinct, but apparently three in a space of 
one line. 
Prof. Sedgwick informs me, that the portion of this remarkable worm which he saw in the rock, and of 
which the specimen described is a part, measured upwards of 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 fossil I know of. The 
piece described is about four inches long, and is gently flexuous. 
Position and Locality.—Tilestone (Upper Ludlow) of Storm Hill, Llandeilo. 
Explanation of Figure—P\. 1. D. fig. 14. Fragment, natural size, from the Tilestone Storm Hill, 
Llandeilo. 
Crossopopra scotica (M/°Coy). Pl. 1. D. fig. 15. 
Ref.—M°Coy, Ann, Nat. Hist. 2nd Series, Vol. VII. 
Sp. Ch.—Length unknown (upwards of two feet), width nearly two lines, width of body (and trail on 
the surface of the beds) one-third of a line; cirri very fine, close, delicate, about five in the space of one line. 
This interesting worm is closely allied to the so-called Nereites Loomisii of Prof. Emmon’s “ Memoir 
on the Taconic System,” t. 3. f. 3, from the-taconic slates of Waterville, Maine. The American species 
