8 F. R. Coiiyet' Reed — 8onie Wenloch S])ecies of Lichas. 



median tubercle. There are only ten segments recognizable in the 

 thorax in the one complete specimen which I have examined, but 

 this probably only indicates immaturity. The pygidium has a large 

 prominent central tubercle near its posterior end ; the transverse 

 roves of tubercles on the axis behind the first ring are very indistinct; 

 the post-axial piece is very short and ill-defined. The Wo pairs of 

 pleurge have their free ends more elongated than is usual, the second 

 pair indeed projecting back behind the posterior end of the pygidium 

 and behind the third pair of spines, which are very short and blunt. 



Fletcher labelled one of these specimens L. BucMandi {=L. anglicus) , 

 but Salter labelled another (a 963) L. hirsutus. From the presence 

 of several specially large tubercles this variety may be termed 

 tuherculatus. 



Lichas (Cokydooephalus), sp. 

 Z. hirsutus (Fletcher), "young" : Q.J.G.S., 1850, vol. vi, pi. xxyii, figs. 7, 7a. 



The pygidium figured by Fletcher as belonging to a young 

 individual of X. hirsutus, "from the great similarity in the arrange- 

 ment of the tubercles on the axis and sides," shows such important 

 differences that it does not seem possible to regard them as merely 

 marking a stage of growth in an individual of this species. The 

 pygidium is semicircular, with three pairs of marginal spines of sub- 

 equal size. The axis is very broad, blunt, and subconical, reaching 

 fully three-fourths the entire length of the pygidium, and occupying 

 considerably more than its middle third. There is one strong ring at 

 the front end of the axis, followed by two or three much narrower and 

 fainter rings marked by tubercles. There is no distinct post-axial 

 piece. The axal furrows are strong and deep. There are two pairs 

 of pleurae on each side (not three 'ribs' as Fletcher states), curved 

 backwards, and ending in short stout, backwai'dly directed free points 

 on the margin. The surface of each pleura is divided down the 

 centre by a strong median furrow, equal in strength to the inter- 

 pleural furrows ; the anterior and posterior parts of each pleura 

 are of equal size and elevation, and each is ornamented by a single 

 row of large tubercles. The posterior pair of spines is rather shorter 

 than the first and second pairs, and its members are twice as closely 

 approximated to each other as they are to the second pair of spines. 

 A few large tubercles are somewhat regularly disposed on the axis 

 and the portions of the lateral lobes behind the second pleuree. 



The margin is strongly and sharply incurved below, and is 

 marked by concentric raised strise, which also cross the under-surface 

 of the spines. 



Measurements. mm. 



Length of pygidium 4 



Width of pygidium 7 



Width of axis ... ... ... ... ... 3 



Eemarks. — It is possible that the specimen above described belongs 

 to an immature individual of some species, though probably not to 

 L. hirsutus. It is advisable, therefore, in the absence of further 

 evidence to leave it unassociated with any of the described species, 

 and to refrain from considering it a new species. 



