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Scientific Intelligence. 



obtained by Mr. Banks, of Kington, and Messrs. Ligbtbody & Cockis, of 

 Ludlow, sbow us that Pterygotus was an elongate crustacean, with a com- 

 paratively small head and sessile compound eyes, few appendages, of 

 which the large chelate antennae are most remarkable, being a foot long 

 and only four-jointed, — the terminal joints forming a strong serrated 

 claw. The large mandibles were fully six inches long ; the maxillae, 

 either one or two pairs, with six-jointed palpi ; and the great swimming 

 feet consisting of six joints, of which the terminal ones were modified as 

 for swimming, and the basal joints are great foliaceous expansions, which 

 possibly assisted, like the joints of the legs in Limulus, in mastication. 

 From the explanations given by Mr. Huxley in the memoir above referred 

 to, there is a general resemblance both in form and structure to the small 

 Stomapod crustaceans, Mysis and Cuma, two minute forms, which must 

 be arranged very low r down in the scale of Decapod crustaceans, and which 

 are also frequently ornamented with a simular sculpture to that of the 

 fossils. There is even a yet greater resemblance in form to the larvae of 

 the common crab. And if this be accepted, the coincidence in essential 

 structure between such minute and embryonic forms and these gigantic 

 denizens of the old seas becomes most remarkable and interesting, as bear- 

 ing on the course of development of life throughout geological epochs. 



5. On the Bone Beds of the Upper Ludlow Bock, and the base of the 

 Old Bed Sandstone ; by Sir R. I. Murchison, (Proc. Brit. Assoc., Au- 

 gust, 1856 ; Ath. No. 1504.) — Sir Roderic Murchison gave an account 

 of the recent and additional discoveries made in those strata, which, 

 whether they pertain to the uppermost beds of the Silurian rocks, or to 

 the lowest junction strata of the Old Red Sandstone, have been grouped 

 under the term of " Tilestones." In his original description of the upper- 

 most Ludlow rock he had described a certain layer, near their summit, 

 as being characterized by the remains of bones of fishes, principally the 

 defences of Onchus, with jaws and teeth, and numerous coprolitic bodies. 

 But he had also noticed, in several localities, the occurrence of a still 

 higher bed, which seemed to form a passage into the Old Red Sandstone, 

 and in which remains of terrestrial plants occurred. He had further 

 pointed out, that the upper Ludlow rock was the lowest stratum in which 

 the remains of Vertebrata were discovered, — an observation which has 

 remained uncontroverted till the present day, no remains of true fishes 

 having yet been detected in more ancient strata in any part of Europe. 

 In an ascending order, however, it was well known that Ichthyolites aug- 

 mented rapidly ; and the object of the present communication is to show 

 how the recent observations of Mr. Richard Banks, of Kington, and of 

 Mr. Ligbtbody, of Ludlow, have made us acquainted with the presence 

 of fish remains in two thin courses above the original bone-bed of the up- 

 per Ludlow rock. The lower of these beds, which, according to the sec- 

 tions exhibited, occurs both at Kington and at Ludlow, was recently in- 

 spected by himself, accompanied by Prof. Ramsay and Mr. Aveline, as 

 well as by Mr. Salter. It is a greyish or yellowish flag-like sandstone, 

 the lowest course of which at Kington contains many spines of Onchus, 

 with* Lingula cornea. This thin layer, and another softer one full of re- 

 mains of Pterygotus and two species of Pteraspis, are surmounted by 

 the blue or grey-hearted building-stone of Kington, with Pterygotus, 



