178 



CHAPTER VIII. 

 PROTOZOIC ANNULATA*. 



Myrianites tenuis (M^Coy). 



Sp. Char. Usually coiled in numerous, small, very irregular un- 

 dulations ; diameter of body about one-third of a line. 



This beautiful little worm is easily distinguished from the 

 M. Macleayi (Murch.) by its very slender proportions, agreeing 

 more nearly in this respect with the M. Murchisoni of Prof. Em- 

 mons's ^' Taconic Slate.^' I think it was about a foot long, from 

 following, as well as I could, the convolutions of three indivi- 

 duals. I have only in one part seen traces of the cirri, which 

 have the same general proportions as in the M. Macleayi{M.m:ch.), 



Not uncommon in a particular layer of the fine olive slate of 

 Greiston, on the Tweed, near Inverleithen. 



{Col. University of Cambridge.) 



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



Etym. Kpoaao^, fimbria', ttov^;, 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, com- 

 pletely 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 pro- 

 tozoic companions, the Nereites and Myrianites, 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. 



Crossopodia lata (M'Coy). 



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

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

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

 space of 1 line. 



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



* The species in this chapter date from the 'Annals ' for May 1851. 



