DE. T. DAVIDSON ON KECENT BRACHIOPODA. 127 



Obs. This small species is nearly related to Krcntssina Lamarckiana, but it is more pouch- 

 shaped, and differs from it in several exterior and interior details. From the shortness 

 of its peduncle, the beak and umbo are generally much worn from friction. Some 

 specimens are ribbed only on the posterior half of the valves, while on others the surface 

 is regularly ribbed throughout. The interior details have been described under Kraussina 

 {MegerUna) Lamarckiana, and need not therefore be repeated. 



75. Kraussina Atkinsoni, Tenison Woods, sp. (Plate XXI. figs. 5, G.) 



Kraussia Atkinsoni, Tenison Woods, Census, with brief deseriptions, of tlie Marine Shells of Tasmania, 

 Proc. Koy. Soc. Tasmania, 1878, p. 57. 



Shell small, somewhat subpeutagonal, widest about the middle, indented iu front. 

 Marginal line Hexuous. Dorsal valve gently convex, divided longitudinally into two 

 lobes by a deep, wide, angular sinus ; lateral sides of the umbo auriculate. Ventral 

 valve deeper than the dorsal one, with a longitudinal mesial elevation or fold ; beak very 

 slightly incurved, pointed, with a rather large incomplete foramen, margined anteriorly 

 by a portion of the umbo of the opposite A^alve and by narrow elongated lateral deltidial 

 plates ; margin-line in front angular. Surface of valves smooth, marked by tine concen- 

 tric lines of growth. Colour light greyish yellow. Length 3 lines by 2^ in breadth and 

 Ij in depth. In the interior of the dorsal valve the hinge-plate is excavated along tlie 

 middle ; septum very slightly elevated, extending from the middle of the base of the hinge- 

 plate to about half the length of the valve. From the anterior extremity of the septara 

 rise two deviating folded lamellse. 



Hub. Dredged at Long Bay, South Tasmania, by the Eev. IL. D. Atkinson, iu 10 

 fathoms water. 



Obs. I am indebted to the Eev. Tenison Woods for my knowledge of tliis well-marked 

 small species. It can hardly be said to have been described, for all that Woods says is 

 that " This is a shell about the size of the last {K. Lamarckiana), but more depressed, with 

 a smooth valve." Kraussijui Atkinsoni is at once distinguished from its congeners by 

 being the only smooth species of the genus with which we are acquainted, and also by 

 the shape of its shell. 



Subfamily ARGioPiNiE. 



In this subfamily we would include the genus Argiope, Deslongchamps, lSi2 

 (=Megathi/ris, d'Orbigny, 1847), and the subgenus Cistella, (iray, 1853, both being 

 closely related to the Terebratulidse, of whicli they form a part, and distinct from the 

 Thecidiidae, which the larger number of zoologists and palaeontologists would form 

 into a separate family. 



W^e are well aware that the name Argiope was j^roposed in 1827 by Savigny and 

 Audouin (Descr. de I'Egypte, ed. 2, xxii. p. 334, pi. ii. fig. 6) for a genus of Egyptian 

 Spiders ; but as tlie name Argiope has been very generally adopted for a genus of Bra- 

 chiopods, I am disposed to retain it for that purpose. 



In Argiope proper there are three or five prominent submarginal septa, the lamella 



