﻿ASTEROLEPID.E. 



213 



P. 5599. Remains of a large trunk, with the right pectoral appen- 

 dage, ventral aspect. Purchased, 1889. 



(ii.) Lethen Bar (typical P. latus). 



P. 533. One of the type specimens of P. latus, figured by Agassiz, 

 op. cit. pi. iii. fig. 4. As remarked by Egerton, the fossil 

 exhibits the ventral aspect, and most of the bone- 

 substance is removed. Egerton Coll. 



28857. Crushed individual, dorsal aspect. The parts of the head 

 are mostly obscured, but the mental plates are distinguish- 

 able, and the pineal or " os dubium," with its median pit, 

 is well shown. The anterior median dorsal plate is 

 almost destroyed, but the smaller second dorsal is more 

 complete ; and immediately below and behind the latter 

 occur the hinder extremities of the posterior ventro- 

 laterals. Nothing worthy of note is presented by the tail ; 

 but in the left pectoral appendage, the transversely 

 striated ginglymus upon which the distal segment moves 

 is distinct. Purchased, 1854. 



49187. Trunk with head and fragments of the appendages and tail, 

 ventral aspect, preserved in counterpart. The head is 

 completely severed from the trunk, and the roof is shown 

 from beneath, of the natural size, in PI. V. fig. 2. In 

 addition to some of the elements ordinarily observed, and 

 marked with letters in the figure, the pineal plate (p.) is 

 well seen, with its central pit, and also one of the orbital 

 plates (o.) ; moreover, a small process is observed to 

 extend from the middle of the anterior margin of the 

 postmedian plate (pi. m.). One of the extra-lateral plates 

 is detached ; and the plates of the 1 '' appendages are 

 scattered and broken. Purchased, 1878. 



49191. Head, trunk, limbs, and scattered remains of the tail, 

 ventral aspect, preserved in counterpart. The posterior 

 ventro-lateral plates exhibit denticulations on the hinder 

 margin. Purchased, 1878. 



50109. Nearly complete individual, dorsal aspect, much crushed, and 

 preserved in counterpart. The specimen is shown of the 

 natural size in PI. V. fig. 3. In the head the most 

 important feature displayed is the pair of mental plates 

 (mn.) ; they are somewhat displaced forwards, and their 

 superior (or visceral) aspect ia distinctly concave. The 



