26 



ASTEROIDEA. 



lowest beds of the carboniferous rocks ; these beds, Mr. Salter kindly informs me, are called 

 by Mr. Jukes and himself the "Coomhola grits" in Ireland, and which Sedgwick and 

 Murchison called the " Marwood beds" in N. Devon : they are neither Devonian nor Car- 

 boniferous, but lie on the confines of both. This asteroid is not yet described. 



Palasterina, McCoy. 



Palasterina primava, Forbes. Mem. Geol. Surv., decade i, pi. i, fig. 2. 



— — Salter. Ann. and Mag. of Nat. Hist., 2d series, pi. ix, fig. 2, 



from which fig. 16 a is copied. 



Body 



broad, 

 Fig. 16. 



Palasterina primma, Forbes, fig. a. 

 „ stellata, Billings, fig. b. 



pentagonal, produced at the angles into five short, lanceolate, or elongato- 

 triangular, pointed arms, which are each about two thirds as 

 long as the breadth of the disc. Surface of the disc convex 

 above («), as well as the arms tuberculated and reticulated, 

 exhibiting traces of having been covered by tufts of short, 

 blunt spines. Madreporiform plate and vent, both subcen- 

 tral. Beneath, nearly fiat ; the inter-ambulacral spaces reti- 

 culated like the upper surface ; the ambulacra composed of 

 broad, oblong, geniculated plates (3), of which there are about 

 twenty in a row. The largest specimens examined had 

 attained the dimensions of an inch and a half in diameter, from 

 arm-tip to arm-tip. This star-fish has many affinities with 

 Asterina or Asteriscus. Mr. Salter has discovered that the 

 " basal or angle ossicula are enlarged, three-cornered, and 

 furnished with a pyramid of spines, pointed inwards. The 

 upper surface is roughly tuberculate, and possesses short tufts 

 of spines." 



■Locality. — Underbarrow, near Kendal, Westmoreland. 

 It is found in a thin, subcalcareous band of Ludlow Rock, 

 loaded with Trilobites and Encrinites. 



Palasterina antiqua, Hisinger. Leth. Suec, tab. xxvi, fig. 6, p. 89. 



Locality. — Mount Hoburg, Gothland, Sweden ; in Ludlow Rocks. 



The Canadian species of Palasterina I have derived from Dr. Billings' valuable paper 

 on the AsteriadcB of the Lower Silurian Rocks of Canada, in the third decade of Canadian 

 Organic Remains. 



