66 ■RURYPTEKIDA. 



HEMIASPIS, H. Woodw. 1864. 



Lhnuloides, Salter, MS., Mus. Pract. Ueol. 



Hemiuspis, H. Woodw. 18135, Quart. Journ. Geol. Soc. vol. xxi. p. 490 ; 

 Murch. 1867, Siluria, p. 518. 

 Distrib-Ktiffii. Upper Silurian. 



Hemiaspis horrida, H. Woodw. 1872. AVenlock Shale, Dudley. 



Hemiaspis horridus, H. Woodw. Geol. Mag. 1872, vol. ix. pi. x. fig. 6, 

 p. 437, woodcut fig. 6 ; id. 1872, Mon. Pal. Soc. p. 179, pi. xxx. fig. G, and 

 woodcut. 



Hemiaspis limuloides, H. Woodw. sp., 1864. Lower Ludlow Piocks, 



Leintwardine, Shropshire. 

 Hemiuspis limuloides, H. Woodw. 1864, Brit. Assoc. Report, sect. C, Bath 

 ]\l3eting: id. 18C5, Quart. Journ. Geol. Soc. vol. xxi. p. 490, pi. xiv. 

 figs. 7 a, 7 c ; II. Woodw. & Salter, 1865, Cat. & Chart Foss. Crust, p. 24 ; 

 Murch. 1867, Siluria, p. 518 ; II. Woodw. 1872, Mon. Pal. Soc. p. 174, 

 pi. xxx. figs. 1, 2, and woodcuts. 



Hemiaspis Salweyi, Salter, 186.5. Upper Ludlow Rock, Ludlow ; 



Lower Ludlow, Ledbury. 

 Hemiaspis Snbvei/i, Salter & H. Woodw. 1865, Chart Fossil Crustacea, fig. 3 ; 

 H. Woodw. 1872, Geol. Mag. vol. ix. pi. x. fig. 4, p. 438, woodcut 

 fig. 7 ; id. 1872, Mon. Pal. Soc. p. 179, pi. xxx. fig. 4, and woodcut. 

 Limuloides tuhercvhdus, Salter, MS. (Museum Pract. Geol.j. 



Hemiaspis sperata, H. Woodw. 1872. L. Ludlow, Leintwardine. 



Hemiaspis sperntus, II. Woodw. Geol. Mag. 1872, vol. ix. pi. x. figs. 5-7, 

 p. 439, and woodcut fig. 5; id. 1872, Mon. Pal. Soc. p. 178, pi. xxx. 

 figs. 5 and 7, and woodcut. 



Limuloides speratus, Salter, MS. Mus. Pract. Geol. 



L. optatus, Salter, MS. ibid. 



PTERYGOTUS, Agassiz, 1844. 



P/eri/f/ofus, Agassiz, 1844, Mon. des Poissons Fossiles, p. xix ; H. Miller, 

 1847, The Old Red Sandstane, 3rd edit. p. 182 ; M'Coy, 1849, Ann. & 

 Mag. Nat. Hist. 2nd ser. vol. iv. p. 393 ; Salter, 1852, Quart. Journ. 

 Geol. Soc. vol. viii. p. 3S6 ; D. Page, 1856, Brit. Assoc. Rep. Glasgow, 

 pp. 89-91 ; Huxlev & Salter, 1859, Mem. Geol. Surv. mon. i. p. 105 ; 

 H. Woodw. 1863,' Intellectual Observer, vol. iv. p. 229; Lyell, 1865, 

 Elements Geol. 6th edit. p. 524. 



Hi7nantopterus, Salter, 1856, Quart. Journ. Geol. Soc. vol. xii. p. 27. 

 Distribution. Upper Silurian and Devonian. 



Pterygotus anglicus, Agassiz, 1844. Old Red Sandstone, 



Forfarshire, &c. 

 Ptertiqottis anglicus, Agassiz, 1844, Poissons Foss. Vieux Gres-rouge, pi. i. ; 

 M'Coy, in Lyell's Elements (1855), 5th edit. ; Salter, in Murch. Siluria, 

 3rd edit. 1859, &c. ; id. 1859, Mem. Geol. Surv. mon. i. p. 67, pis. iii.-vii. ; 

 H. Woodw. 1865, in Lvell's Elements of Geology, 6th edit. p. 524, 

 tig. 591 (restored) ; id. Mon. Pal. Soc. 1866, Merostomata, pt. 1, p. 33, 

 pis. i.-viii. 



Pterygotus arcuatus, Salter, 1859. L. Ludlow Rock, Leintwardine. 



Pteri/yot^is arcuatus, Salter, 1859, Memoirs Geol. Surv. mon. i. p. 95, pi. xiii. 

 figs. 8, 12, 13, 15, and 16; H. Woodw., 1872, INIon. Pal. Soc. Merostomata, 

 pt. 3, p. 88, woodcuts figs. 21-23 ; Salter, 1873, Cat. Camb. & Sil. Foss. p. 165. 



