45 



ASAFHUS L ATI co STATUS.* Green. Cast No. 13. 



Cauda praelonga, pars ad marginem vix membra- 

 nacea; cute coriacea, tuberculis minimis; costis lads, 

 convexis et valde clistinctis. 



The fragments of this species, which we have exa- 

 mined, comprise ten articulations of the middle lobe, 

 and the corresponding ribs of the sides, all in a very 

 good state of preservation; the extent to which the 

 membranaceous expansion reached beyond the tail and 

 the lateral lobes is very apparent, but it has been un- 

 fortunately broken off all round. Our specimen ap- 

 pears to be a natural cast of the internal part of the 

 shell, or the coriaceous covering of the animal. 



The portion of this specimen of trilobite which 

 still remains perfect, is two inches long, and three 

 inches and a quarter broad. The middle lobe exhi- 

 bits the appearance of a very exact and gradually ta- 

 pering cone, its articulations being rounded and 

 slightly flattened on the top. The ribs of the lateral 

 lobes are nearly straight, slightly arched, broad, 

 rounded, and gradually increase in width from the 

 point of their insertion; they are simple or not bifur- 

 cated throughout, and are covered with very minute 

 granulations, which are probably produced by the 

 sandstone in which the animal is mineralized. The 

 membranaceous expansion near the caudal termina- 

 tion, is a good deal prolonged. 



The A. Laticostatus occurs in a light coloured fer- 



* From the Latin for " broad ribbed." 



