128 



DE. T. DAVIDSON ON EEUENT BRACHIOPODA. 



forming the loop being four-lobed, adhering to the septa, and more or less confluent with 

 the valve. 



In CisteUa there is but one prominent submarginal septum, the loop, or semicircular 

 lamella, being two-lobed. In the first the labial appendages are folded into four lobes, 

 in the second into two. 



The animal and its embryology have been carefully studied, described, and illustrated 

 by such excellent observers as W. Dall, Kowalevsky, A. E. Shipley, M. A. Schulgin, and 

 S. P. Woodward, as well as by myself and others, and these investigations will be fully 

 alluded to in the description of the species. 



We know with certainty of but one species of At^giope in the recent condition, the 

 Argiope decollata of Chemnitz. To this section Schulgin would add the A. Barroisi 

 Shnd A. globuliformis; hut as I have never seen those two species or their interiors, I 

 cannot feel certain whether they should be classed with Argiope or with Clstella. 



We are acquainted with the following eight or nine recent species of the genus CisteUa, 

 viz. : — 



1. CisteUa neapolitana, Scacchi, 1833. 



2. ■ Koivalevskii, Schulgin, 1884. 



3. cisteliula, S. Wood, 1840. 



4. IVoodwardiana, Davidson, 1866. 



5. cuneata, Risso, 1826. 



6. CisteUa Barrettiana, Davidson, 1866. 



7. Schrammi, Crosse, 1866. 



8. 

 9. 



liitea, Dall, 1870. 

 lunifera, Philippi, 1836. 



76. Argiope decollata, Chemnitz, sp. (Plate XXI. figs. 30-35.) 



Anomia decollata, Chemnitz, Conch.-Cab. vol. viii. p. 96, pi. Ixxviii. fig. 70.5, 1785. 

 Anomia detruncata, Gmelin, Syst. Nat. p. 3347, 1788. 

 Terebratula ungula, Retzius, Nov. Gen. Test. 1788. 



Terebratula detruncata, Bruguiere, Encycl. Meth. tab. 243, fig. 10, 1789. 

 Anomia detruncata, Dillwyu, A Descrip. Cat. of Shells, p. 292, 1817. 

 Terebratula detruncata, Blainville, Diet. Sc. Nat. vol. liii. p. 141, 1828. 

 Terebratula aperta, Blainville, Diet. Sc. Nat. vol. liii. p. 144, 1828. 



Terebratula decollata, Deshayes, Encycl. tab. ccxliii. fig. 10, 1830; Cantraine, Bull. Acad. R. des 

 Sciences de Bruxelles, 1835. 



Terebratula dimidiata, Scacchi, Osserv. Zool. p. 17, 1833, and Cat. Conch. Regni Neapolitani, p. 8, 1836. 

 Terebratula detruncata, Scacchi, Cat. Conch. Regni Neapolitani, p. 8, 1836. 



Terebratula urna antiqua and T. cardita, Risso, Fauna Europ. Mer. vol. iv. pp. 387, 389, pi. xii. 

 figs. 177, 180, 1826. 



Terebratula decollata, Lamarck, An. sans Vert. ed. 2, vol. vii. p. 350, 1836. 



Terebratula detruncata, Philippi, En. Moll. Sicilije, vol. i. p. 96, tab. vi, fig. 14, 1836. 

 Arr/iope decollata, E. Dcslongchamps, Mem. Soc. Linn, de Normandie, vol. vii. p. 9, 1842. 



Orthis detruncata, Philippi, En. Moll. Siciiise, vol. ii. p. 69, 1844. 



Terebratula detruncata, Forbes, Rep. on the Moll, of the ^gean Sea, p. 141, 1844; D. Galvani, 111, 

 delle Couch, fossili, 1845. 



Terebratula decollata, G. B. Sowerby, Thes. Conch, i. p. 355, pi. Ixxi. figs. 68-70, 1846. 



Megathyris detruncata, A. d'Orbigny, Comptes Rendus Acad, des Sciences, 1847; Annales des 

 Sciences Nat. Zool. 3'' ser. vol. viii. p. 341, 1847; Paleontologie Fraufaise, Ter. Cret. vol. iv. p. 146. 



