﻿218 ANTIARCHA.. 



28359, 39175. Much crushed individual, in counterpart, exhibiting 

 the lateral and partly dorsal aspect. The elements of the 

 head are almost unrecognizable, and those of the trunk 

 and appendages are imperfectly displayed. The dorsal 

 fin upon the tail is distinct, with remains of its fulcral 

 6cale ; and more posteriorly is observed the series of large 

 dorsal ridge-scales. 



Purchased, 1854, and Bowerbanh Coll. 



4S188. Head, trunk, appendages, and fragment of tail, ventral 

 aspect, preserved in counterpart. In the head, the " os 

 dubium " or pineal plate, with its central pit, is well shown. 



Purchased, 1878. 



50108. Large specimen wanting the tail and the extremities of the 

 appendages. The trunk measures 0*078 in length, ex- 

 hibiting the ventral aspect, and the roof-plates of the head 

 are seen from beneath. Most of the latter are well shown, 

 and as their substance is partly destroyed, the course of 

 the sensory canal upon the laterals and premediau can 

 be traced. The extra-laterals are detached. 



Purchased, 1879. 



50111. Well-preserved specimen, ventral aspect, in counterpart, the 

 impression shown of the natural size in PL YI. fig. 2, and 

 explained by the lettering. The tail is somewhat twisted, 

 thus exhibiting the dorsal fin. Purchased, 1879. 



50113. Small specimen, wanting the tail, ventral aspect. 



Purchased, 1879. 



P. 3211. Much crushed specimen, ventral aspect, wanting appen- 

 dages. EnnisTcillen Coll. 



P. 4037. Small head and trunk, ventral aspect, in counterpart. 



Purchased, 1883. 



(ii.) Tynet Burn. 



44588. Small imperfect crushed specimen, ventral aspect. 



Purchased, 1873. 



(iii.) Edderton, near Tain. 

 P. 1172. Much crushed and broken individual. Egerton Coll. 



(iv.) Orkney (typical P. cancriformis). 

 P. 532. One of the type specimens of P. cancriformis figured by 



