76 BRITISH FOSSIL CRUSTACEA. 



Species 5.— PTERYGOTUS TAURINUS :— Salter. 1868. Woodcut, Fig. 14, p. 75. 



Pterygotus taurtnus, Salter. Report Brit. Assoc, Norwich Meeting, 1868. Trans, 

 of Sections, p. 78. 



This new species was obtained from the lowest Old Red, or Ledbury Shales formation. 

 It is a very large one, and must have measured 7 feet in length when perfect. Its head is 

 very square ; the base of the swimming-foot small in proportion to that of other species. 

 The chelate antennae have the apices very greatly hooked and the teeth close. Only 

 fragments of the body-rings have been found. The tail-joint appears to have been oval. 

 The specimens were found at Ewyas Harold, and are in the cabinet of Dr. McCullough, 

 of Abergavenny. 



The Woodcut, given on page 75, is reproduced from an original sketch by the late 

 Mr. J. W. Salter, drawn at the time his note was written. The parts known only are 

 shaded ; the outline was intended by Mr. Salter to convey an idea of the general form. 



Measurements given by Mr. Salter : — 



1. Head a foot wide. 



2. Portion of chelate antennas preserved, 6 inches long. 



3. Portions of two palpi, 4 inches. 



4. Basal portion of swimming-foot, 5 inches. 



Species 6.— PTERYGOTUS LUDENSIS :— Salter. 1859. PL XVI, figs. 7—9. 



Pterygotus Ludensis, Salter. Mem. Geol. Siirv., Mon. I, 1859, p. 79, pi. xiv, figs. 

 1 — 13 ; pi. ix, fig. 18 ? ; pi. xii, figs. 1—5 (and 6 ?). 

 — — Salter. Siluria, 4th edit., 1867, p. 140, and p. 238. 



Under this name Mr. Salter describes, with but little doubt of its specific distinct- 

 ness, the fragments of a fine species very abundant indeed in the transition beds of 

 Ludlow, shown as they are in the railway cutting near that town. All the specimens are 

 in the cabinets of Mr. Lightbody and his son. The same species is found at Trimpley, 

 near Kidderminster, and we are indebted to the late Mr. G. E. Roberts for the means of 

 illustrating some points not clear in the specimens at Ludlow. 



The materials consist of several body-rings 1 of a large size (PI. XVI, figs. 7 and 8) ; 

 a fragment of the caudal joint ; 2 a specimen showing nearly all the body-joints and telson 

 in position, but a good deal obliterated ; the serrate basis of the swimming-feet, man- 

 dibles with palpi, antenna? ; and to these must be added the post-oral plate, the bilobed 



1 Mem. Geol. Surv., Mon. I, pi. xiv, figs. 2, 3, 4, 11 : these are all fragments merely.— H. W. 



2 Ibid., fig. 12 ; only a fragment. 



