BIBLIOGRAPHY OF THE MEROSTOMATA. 23 
“believed that this might be the type of a peculiar genus of fishes, and to that class I 
referred Pterygotus in my enumeration of the fossil fishes of the Silurian system, pub- 
lished in Murchison’s great work” (1839). The discovery of more perfect remains in 
Scotland convinced Agassiz that they must be Crustacea. He adds, “I am rather 
inclined to believe that this singular animal will become the type of a family interme- 
diate between the Ziilobites and the Hntomostraca, in which, perhaps, the Huryptert and 
the Hidothee will some day be included.” 
21. 1845. The Rev. P. B. Bropm, M.A., F.G.S.,% in his ‘History of Fossil 
Insects,’ describes and figures a curious fossil in clay-ironstone from Coalbrook-dale 
resembling the Caterpillar of the Emperor Moth (Saturnia pavonia-minor). This has 
since been described (1863) by Mr. J. W. Salter, as Hurypterus (Arthropleura) ferow. 
22. Dr. H. Burmutstsr,” in his systematic arrangement of Trilobites, &c. (1846), 
makes the Hurypteride the first family of the tribe Paleade, which, he observes, are 
“characterised by the possession of two large compound eyes, by the absence of 
secondary eyes, and by having short undeveloped feelers and soft leaf-formed feet, bearing 
gills,’ &c. Of the Hurypteride he says, “In these there is no shell. The head, whose 
position is very distinct, bears two pairs of setaceous feelers and one pair of accessory 
parts of the mouth. ‘There are probably nine (?) rings in the thorax, the first of which 
bears a pair of very large rudder-shaped feet, furnished with five joints, and the suc- 
ceeding rings seem to have borne similar leaf-like feet of an equal size. The abdomen 
consisted of three or six rings, and was terminated by a pair of rudder-fins (?).” 
23. 1847. HucnH Miter” gives an interesting description of Agassiz’s first 
examination of the remains of Péerygotus in Mr. Webster’s collection from Balruddery ; 
and he figures a portion of a foot-jaw (supposed at that time to be a tail-lobe). 
24. In 1850 Dr. H. B. Gurnirz” figures and describes a fossil remain from the 
Chalk formation (Lower Planer) of Plauen in Saxony, which he names Limulus Steinle. 
Not having seen the original specimen, we should hesitate to deny its crustacean cha- 
racter ; but we see no evidence of its affinity to Zimudus, judging from the figure given. 
25. Dr. Ferpivanp Romer,” in 1851, gave a notice of Hurypterus, in which he 
suggested the affinity of that genus with Zimulus; pointing out, however, the great 
difference in the feet, &c. 
26. Mr. J. W. Satrer,” in 1852, figured and described two fragments of the chelate 
appendages of Plerygotus problematicus, Agassiz, from the Upper Ludlow Rock, Here- 
fordshire. 
27. M. Ep. von Ercuwaxp,” in 1854, gives figures of Hurypterus tetragonoph- 
thalmus of Fischer, which—as Mr. James Hall has pointed out—he erroneously ascribes 
to #. remipes of Dekay. He also figures a perfect segment of Pterygotus, which he 
ascribes to P?. Anglicus, Ag. He considers that Hurypterus and Pterygotus were very 
closely allied genera. M. von EHichwald’s specimens are from the Island of Cisel, in the 
Baltic. 
