BIBLIOGRAPHY OF THE MEROSTOMATA. . 2 
living family, and was in aspect more like the larvee than the adult forms of any Crus- 
tacean with which we are acquainted.” 
35. Later in the same year Sir R. I. Murcutson® gave an account of the discovery, 
by Mr. Robert Slimon, of a remarkable series of Pterygotian remains at Lesmahago; 
Lanarkshire, in which he observes that the uppermost Silurian Strata in Russia, in 
England, and in North America, are characterised by the presence of Pterygotus and 
Lurypterus, associated with small Zingwe and other fossils. 
36. 1856. Mr. J. W. Satrsr” follows with a description and figures of a new genus 
of Pterygoti, viz. Himantopterus, of which he there gives notice of six species, namely, /. 
maximus and acuminatus (now united in Slimonia acuminata), H. bilobus, H, perornatus, 
H. Banksui (now referred to Plerygotus) and /. /anceolatus (since referred to Hurypterus). 
37. 1856. Prof. T. H. Huxtny* adds some observations on the structure and 
affinities of Himantopterus. ‘The conclusion he draws is that “The nearest approach to 
Himantopterus which could be constructed out of the elements afforded by existing 
Crustacea would be produced by superinducing, upon the general form of a Cumoid 
Crustacean, such a modification of the appendages as we find among the Zoform 
Macruran larve.’’ In fact, that Himantopterus bears a strong similarity to a larval form, 
but is not itself therefore to be considered embryonic. 
38. In 1856 Dr. H. Jorpan and Hermann von Meyer® described a curious 
(blind) Crustacean from the Culm-formation of Saarbruck under the name of <Adel- 
ophthalmus (Hurypterus) granosus, Jord.; also the fragment of a second remarkable form 
which is named Arthropleura armata, Jord. 
39. 1856. Mr. Davin Pacn® gives figures of Plerygotus, Himantopterus, Stylonurus, 
and Slmonia, and observes, “ Respecting these Crustaceans, their place is altogether 
unknown in zoology, there being, as it were, an interfusion of phyllopod, pcecilopod, and 
decapod,—of brachyurous, macrourous, and xiphosurous forms.” 
40. In Prof. T. H. Huxuiny’s*® ‘ Lectures on Natural History,’ published November 
7th, 1857, appears the following description of the Huwrypterida :—“ This group includes 
the Devonian and Silurian genera Eurypterus and Pterygotus, which, though as little 
embryonic in their characters as the Zri/odcta, are, in many respects, curiously larval. 
These singular Crustaceans attained a very great size, species of Péerygotus of several 
feet in length beg known. The body, in those forms which have been most carefully 
examined, consists of a comparatively small carapace, rounded anteriorly, and carrying on 
its upper surface a pair of elevations, which are distant in Pterygotus and approximate in 
Lurypterus, and were, in all probability, the eyes. 
“'Ten to twelve distinct segments succeed the carapace, becoming narrower posteriorly 
to the last, varying in shape from lanceolate to oval, and deeply emarginate, probably repre- 
sented a telson. 
“Three pairs of appendages were attached to the carapace in Pferygotus—anterior 
pincer-like antennz; median toothed mandibles, provided with a large palp; and a pair 
