Description of Genera and Species. 23 



was quite wrong in assigning it and nearly allied forms to the inacrurous Decapods. 

 The wide sternal arches so characteristic of this group of Schizopods are almost in- 

 variably shown in the compressed specimens, as in fig. 1, which is a reproduction from 

 the original drawing for fig. 3b of plate viii. of vol. xxx. of the Transactions of the 

 Koyal Society of Edinburgh. It also shows the characteristic telson of this group. 

 Fiy. 2, also a reproduction of fig. 3 of the original description, shows the longitudinal 

 keels on the carapaces plac^ed as in (riiathophausia. The chief points in which this 

 species differs from those just described are its much greater size, which averages 

 from 30-40 nnii. in length, the nature of its integuments, which have a distinct 

 grained pattern upon all the dor.sal parts where friction does not come into play, and 

 in having serrations on the median longitudinal keel, both in front of and behind the 

 cervical fold and on the edsies of the rostrum. From T. loudonensis it differs in having 

 the median keel of the carapace carried right back to the posterior margin, while it 

 differs from T. woodwardi in the tail having a trace of the median longitudinal keel 

 only upon one of its segments, wliile, in the latter form, three distinct keels are found 

 on the tail segment.s. 



Locality. — Eiver Esk, Glencartholm, Langholm, Dumfriesshire. 



Horizon. — Scorpion-bed, Calciferous Sandstone Series. 



Collector. — A Macconochie. 



Tealliocauis etiieiudgei, var. i-ata Peach. PI. III., figs. 3, 4. 



1883. AnthrapalcBmon etheridgii, var. latus B. N. Peach, Trans. Roy. Soc. Edin., 

 vol. XXX., p. .513, pi. xxviii., figs. 4-4b. 



Remarks. — This variety is in all otlier respects like T. et/ieridi/ei except that it is 

 shorter and broader in its proportions. Its breadth compared witli its length is as 1 to 

 2-|-, when in the latter it is as 1 to 3. The carapace is broader than long, while that of 7". 

 etheridgei is the reverse. 



This form occurs in the Scorpion-bed at Langholm along with 7'. etheridgei in about 

 the proportion of one of the former to one hundred of the latter. 



Locality. — Glencartholm, Langholm, Dumfriesshire. 



Horizon. — (Scottish) Calciferous Sandstone Series. 



Collector. — A. ^lacconochie. 



