ENCRINURUS PUNCTATUS. 121 



1873. Encrinurus punctatus, Salter, Cat. Camb. Silur. Foss. Woodw. Mus., pp. 77, 131. 



1874. Encrinurus punctatus, Steinhardt, Die preuss. Geschieb. gefimd. Trilob. (Beitr. Naturk. 

 Preuss. Phys. Oekon. Gesell. Konigsberg., st. 3), p. 58, pi. iv, fig. 15. 



1875. Encrinurus punctatus, Baily, Char. Brit. Foss , p. 50, pi. xvi, fig. 12 ; p. 67, pi. xxiii, fig. 2. 



1876. Encrinurus punctatus, Eoemer, Leth. Geogn. I, Atlas, pi. xvii, figs. 8 a, b. 



1877. Encrinurus (Cybele) punctatus, Woodward, Cat. Brit. Foss. Crust., p. 36. 



1878. Crijptonijmus punctatus, Vogdes, Monogr. genera Zethus, Cybele, Encrinurus, and Cryptony- 

 mus (Charleston), p. 18. 



1879. Encrinurus punctatus, Nicholson and Etheridge, Mon. Silur. Foss. Girvan, fasc. i, p. 109, 

 pi. viii, figs. 1 — 3, non fig. 4. 



1881. Encrinurus jninctatus, Schmidt, Eev. Ostbalt. Silur. Trilob., pt. i, p. 225, pi. xiv, figs. 11—13 ; 



pi. xv, fig. 18. 

 1886. Encrinurus punctatus, Novak, Studien an Hypost , IV (Sitzb. biJhm. Gesell. Wiss.), p. 429, 



pi. i, figs. 1—8. 

 1888. Encrinums punctatus, Wigand, Zeitschr. deutsch. geol. Gesell., vol xl, p. 91, pi. x, fig. 23. 

 1890. Encrinurus punctatus, Pompecki, Die Trilobf. Ost.-West-preuss. Diluv. Geschieb. (Beitr. 



Naturk. Preuss. Phys. Oekon. Gesell. Konigsberg, st. 7), p. 40, pi. v, figs. 21, 22 ; pi. vi, fig. 32. 

 1893. Encrinurus punctatus, Vogdes, Bibliogr. Pal. Crust. (Calif. Acad. Sci.), p. 308. 

 1899. Encrinurus punctatus, Mem. Geol. Surv., Silur. Rocks Brit., vol. i, Scotland, pp. 503, 505, 



529, 530, 532, 536, etc. 



Remarhs. — As Nicholson and Etheridge have remarked (op. cit., p. 109), the 

 variety arenaceus is much commoner than the variety calcareus in the Girvan 

 district. The specimens from Penkill (Nicholson and Etheridge, op. cit., pi. viii, 

 figs. 1, 3), Camregan Wood, Bargany Pond Burn, and Newlands are like the 

 typical Wenlock examples from Dudley, and have a pygidium with the axis 

 possessing a median smooth space bearing a tubercle opposite every fifth or sixth 

 ring, the rings not being complete in the centre, as Salter mentioned (pp. cit., 1853). 

 The specimens, on the other hand, from Woodland Point and Mulloch Hill (op. cit., 

 pi. viii, fig. 2) have no clear space down the middle of the axis, as the rings are 

 continuous across it, and there is no median row of tubercles. In other respects 

 the pygidia appear to be identical. The head-shields are not sufficiently preserved 

 to feel sure of any points of difference, but the glabella in those of the second 

 group appears to be relatively somewhat longer and to have a more slender neck. 



None of these Silurian specimens have the mucro to the pygidium well 

 preserved, but it appears to have existed in some of the above-mentioned examples 

 from Penkill, Bargany, Newlands, and Camregan, and these specimens therefore 

 belong to the variety calcareus, which, as Salter stated, is the common Wenlock 

 variety. 



The Ordovician representatives of the species, on the other hand, resemble 

 those from Mulloch Hill and Woodland Point. The axial rings are continuous 

 across the axis and fewer in number (18-25) than in the other form. The pleura? 

 and rings are finely granulated, and no definite row of tubercles exists on the axis 

 or elsewhere. In all the tail ends abruptly, as in the variety arenaceus. 



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