36 Descrij)tion of (xenera and Sj^ecies. 



a small form. Epipodites in GnatlaipliaaMa are set with sensory hairs, and appear to 

 function as gill cleaners. The function of the present plates, whether they be the 

 expanded basal joints of the legs or epipodites, appears to be protective to the gills, 

 lobules and filaments of which are shown in tlie areas between the margins of the plates 

 and the divisions between the sternites (fig. 2). The natural inference is that they may 

 be breeding lamelte^ ; but the two organs placed at the posterior margin of the 

 seventh sternite suggest that the remains are those of a male. 



Only the uropods of the sixth tail segment have been observed (fig. 5). They con- 

 sist of a flattened, short triangular-shaped propodite, with the characteristic ornamentation 

 , and median crest. The exopodite is broad, flattened, and leaf-like. It is strengthened 

 along its outer side in the usual manner, and appears to have supported a row of spines 

 and bristles and to have terminated in the usual spine. The inner side is more web-like 

 and set with setse. There is the usual terminal lobe separated by the transverse suture, 

 and this is fringed along its outer margin by setaj. The endopodite is also very broad, 

 subquadrate, and leaf-like. Its outer margin is minutely serrated, and its posterior outer 

 angle is a sharp point. Its posterior margin forms a sigmoid curve, and is fringed with 

 setEe. 



Zot'ato?/.— Greengairs, 3^ miles N.N.E. from Airdrie, Lanarkshire. 



Horizon. — Soft band ironstone. Lower Coal Measures, " Lanarkian." 



Collectors. — E. Dunlop and D. Tait. 



Anthrapal^mon russellianus, var. spinulosus var. nov. PL IV., fig. 7. 



There appears to be a considerable amount of variation in the carapaces of this 

 species, especially in the number and size of the spines with which the embossed portions 

 are studded and also in the number of the sen-ations alono- the edge of the 

 lateral keels. 



General Description. — There is, however, a form which recurs that is altogether 

 more deUcately constructed and in which the proportions are somewhat diSerent from 

 the central species, and which may, when more is known of the animal to which it 

 belongs, eventually entitle it to specific rank. Fig. 7, T. 2768", shows such a carapace 

 flattened out in the manner in which the fossil is usually found. The rostrum is more 

 slender than in the parent species, the anterior margin between the rostrum and the 

 antero-lateral spnie is wider, the spine itself is smaller, and the serrations on the edge 



' Tliis inference receives strong support from the description of breeding lamella; upon Pygocephalus 

 cooperi Huxley, by Dr. Henry Woodward, while this monograph was in slip proof. See Geol. Mag. Dec. v., 



vol. iv., 1907, pp. 400-407, pi. xviii., and text figures. 



