474 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [May 2, 



greater abundance than any other which occurs among the sandstones 

 at Barlae. It is usually found in the form of long, rounded, straight, 

 or slightly-curved bodies, of which the latter portion of the generic 

 term well expresses the appearance. Sometimes individuals are 

 found which have the aspect of having been subjected to sudden 

 force, presenting themselves sharply bent at a right, or even an acute 

 angle, showing that their succulent tissues had been injured by 

 breaking. This form has a great resemblance to Scolithus linearis. 

 Hall, from the Potsdam sandstone, where it occurs in a straight 

 state. The American fucoid* is, however, found traversing the 

 rock in a perpendicular direction, while the Scotch Palceochorda 

 major is met with scattered horizontally over the faces of the strata. 

 McCoy's specimens are from Kirkfell, near Scawgill. 



4. Pal^ochorda? teres, nov. sp. This species (if it belongs 

 to the genus Palceochorda) , may be recognized by the gradual taper- 

 ing of the stems, which are much broader at what appears to be the 

 base than at the opposite end. The length is also much less than 

 in P. major. But the thinning of this form is its most distinguishing 

 characteristic. In one of the specimens the apparent base is j^ths 

 of an inch across, while the opposite extremity is only -j^th ; the 

 whole length of the specimen, as it now appears, being only about 

 3 inches. 



This species, which appears to have been well rounded, seems to 

 have been much shorter than the other forms of the Palceochorda 

 which make their appearance in the Lower Silurians of Great Bri- 

 tain. 



Locality. — Associated with P. major and other fossils in the hard 

 shales and sandstone beds of Barlae. 



5. TRiCHOiDEsf AMBiGuus, uov. gcu. ct spcc. Thcsc Speci- 

 mens, the nature of which is uncertain, consist of hair-like bodies, 

 generally straight, but sometimes having a slight curve. They 

 occur scattered over the faces of some of the beds in an irregular 

 manner. They sometimes, however, seem to be collected in groups, 

 the hair-like forms having an arrangement approaching to imperfect 

 radiation. Some of the scattered portions have the aspect of bifur- 

 cation; but this, perhaps, may be owing to two individuals coming in 

 contact with each other. When magnified, the surface seems to have 

 a serrated aspect, somewhat resembling the serratures which mark 

 Graptolites of the genus Diplograpsus, but much more minute. The 

 length of the hair-like bodies is irregular; sometimes they exceed 

 an inch, and at other times they are much less, having a broken 

 aspect. Whether these bodies be Fucoids, or Zoophytes allied to 

 Graptolites, is at present difficult to say. Their apparent branching, 

 and the serratures which occur on their side, would lead to the con- 

 clusion that they belong to the latter ; and the late Prof. E. Forbes, 



* Regarded by Mr. W. E. Logan as the cylindrical casts of vertical Worm-holes. 

 See Quart. Journ. Geol. Soc. vol. viii. p. 200. 

 t From Gr. rpixoet^})s, hair-like. 



