BRACHIOPODA. 
113 
continuing into the layers beneath, but producing a superficial ornamentation not 
unlike that occurring in Eichwaldia. This ornamented layer extends even over 
the surface of the deltidium. The inner laminae of the shell are fibrous and 
more sparsely punctated. There is no deltidial tube in the umbonal cavity of 
the pedicle-valve. The hinge-plate has not been completely demonstrated, but 
it appears to be similar to that of Rhynchospika, with no prominent posterior 
extension, but with conspicuous crural bases which are curved upward. The 
whole process is supported by a well defined median septum. The spiral rib¬ 
bon makes but few (four or five) volutions; the loop takes its origin behind 
the middle of the primary lamellae, its lateral branches being slightly constricted 
near their bases; it is inclined backward in a broad curve, the union of the 
lateral branches taking place at a point just within 
the opposite side of the base of the cones. From 
this point the stem of the loop is continued as a 
simple process, outward between the coils and 
almost to the inner surface of the pedicle-valve. 
Genus UN CITES, Defrance. 1827. 
PLATE LII. 
1776. Terebratula, Bedth. Julise et Montium Subterranea, etc., p. 134. 
1822. Terebratulites, Schlotheim. Petrefacktenkunde, pi. xix, fig-. 1. 
1827. Uncites, Defrance. Bull, des Sciences, vol. xii, p. 152. 
1834. Terebratula, von Buck. Ueber Terebrateln, p. 69. 
1851. Uncites, Quenstedt. Handbuch der Petrefacktenkunde,'p, 459, pi. xxxvi, tig-. 40. 
1853. Uncites, Davidson. Inti-od. British Fossil Bi-achiopoda, p. 89, pi. vii, tigs. 79-86. 
1855. Uncites, The Sandbergers. Verstein. der rhein. Schicht. Syst. Nassau, p. 333, jil. xxxi, fig. 5. 
1864. Uncites, Davidson. British Devonian Bi-achiopoda, p. 22, pi. iv, figs. 11, 12. 
1871. Uncites, Quenstedt. Petrefacktenkunde Deutschl.; Brachiopoden, p. 231, iil. xliii, figs. 46-55. 
1881. Uncites, Davidson. Geological Magazine, new ser., vol. viii, p. 145. 
1882. Uncites, Davidson. British Devonian Bi-achiopoda, Supple., p. 30, figs. 1, 2. 
Diagnosis. Shells usually of large size, elongate-oval or subtriangular in 
marginal outline; valves convex. The pedicle-valve has a long and acuminate 
beak which is always arched or incurved and frequently distorted. There is 
no cardinal area and the hinge-line is greatly curved. There is no foramen in 
mature individuals though it may be retained in young forms. The deltidium 
is concave and consists of a single piece, all trace of the original components 
Fig. lOi. The loop of Ptychospiraferita, 
von Buch. (C.) 
