of Recent Brackiopoda. 373 



processes : the loop is folded into two or more lobes occupying 

 the interspaces of the radiating septa, to which they adhere on 

 their inner side. The mantle adheres closely to the shell, as in 

 Terebratula proper, and is not seen, except as a part of the shell : 

 its margin is simple and not ciliated ; the arms originate as in 

 Terebratula on the anterior side of the mouth, and diverge right 

 and left parallel with the margin of the shell, but at some little 

 distance from it : when they arrive at the raised septa they turn 

 inwards, forming one or more lobes on each side of the middle 

 line : the outline of the arms is therefore four-lobed in A. decol- 

 lata ; whilst in other recent species, such as A. cistellula, which 

 has only one, there is only one lobe to each arm. The arms are 

 relatively connected, as in Terebratula, by a membrane filling up 

 the whole interior space. 



43. Argiope decollata, Chem. sp. 1785 ; detruncata, Gmel. 1788. 



Sow. Th. Conch, pi. 71. fig. 68, 70. 



Hab. Mediterranean : depth from 45 to 105 fathoms ; fossil. 

 Miocene, Gibraltar. (James Smith.) 



44. Argiope cuneata, Kisso sp., 1826; Sow. Th. Conch, pi. 70. 



fig. 83, 84. 



Ter. Pera, Miihlfeld. 



Hab. Mediterranean : depth from 28 to 69 fathoms (Forbes). 



Obs. This species has only a single median septum. The lobes 

 of the loop are free for one half their extent in the specimen 

 examined, and then blend with the shell, as we have noticed in 

 some specimens of A. decollata. 



45. Argiope Forbesii, Dav. 1852. 



T. seminulum and lunifera of Sow. Th. Conch, pi. 71. fig. 85- 

 88 (non T. seminulum, Philippi). 



Hab. Mediterranean : depth from 60 to 105 fathoms (Forbes). 

 Obs. In this form the same longitudinal septum exists, but 

 the loop was imperfect in the specimens at my disposal. 



46. Argiope cistellula, S. Wood, sp. 1840 ; Mag. and Ann. of 



Nat. Hist. vol. v., and Forbes and Hanley, Hist, of Brit. 

 Moll. pi. 57. fig. 9, 1849; Dav. Mon. of Tertiary Brach. 

 Pal. Soc. part 1. p. 10. f. 2. 



Hab. Off Skye, Zetland, &c, Scotland; in 40 fathoms (M'An- 

 drew) . 



Obs. In this species the same mesial septum coexists with a 

 complete two-lobed loop ; in my specimen of this species the ani- 

 mal is preserved, and differs only from A. decollata in having two 

 lobes instead of four. 



