General llistori/ of tlin .^furine Polyzoa. 329 



distinctive features of M. Peachii are present in my variety — 

 the sniallcr cell, the absence of striation on the front wall, 

 the less massive mucro, and the comparative smallness of the 

 oral denticle. The two forms are probably distinct ; Mr. 

 Busk's tio-ure in the 'Challenger' Report can hardly be 

 referred to the var. octodentata. 



M. Peachii and M. ventricosa are closely allied species 

 and have recently been united by Lorcnz. They are liable 

 to much variation, but there is a strongly marked character 

 about the normal M. ventricosa. 



Ibid. (p. 66 Sep.). 



Mucronella tricuspisj sp. n. 



Syn. Exochella longirostris, Jullien, Mission du Cap Horn, Biyozoairea, 

 vol. vi. 1888, p. 55, pi. iii. figs. 1-4. 



I can see no difference of any moment between this species 

 and Exochella longirostris^ Jullien. The pores round the 

 margin of the cell in the latter are wanting in my specimens 

 of M. tricuspis ; but this is a variable character and has no 

 diagnostic value. The diflference may be due to the degree 

 of calcilication. Except in this one particular there is a close 

 agreement between Dr. Jullien's figure (fig. 4), which is an 

 admirable one, and my own. 



As for the genus Exochella, it seems to me to be super- 

 fluous. It is founded on a single character of no special 

 importance — the elongate tooth on the lower margin of the 

 orifice, " forming a kind of spur," and dividing the lower lip 

 of the peristome into two distinct portions. It genera are to 

 rest on such slight foundations they may be indefinitely 

 multiplied and will lose altogether their significance and value 

 as representative of leading morphological types. 



Additional Loc. Tierra del Fuego ; Chiloe Archipelago 

 {Darwin) ; Simon's Bay, Cape of Good Hope ; Prince 

 Edward Island, 80-150 fath. {Busk, ^Chali: Hep.); Port 

 Phillip Heads and New Zealand {MacG.). Fossil : Petane 

 ( Waters) ; He Hoste, bale Orange ; Canal du Beagle, au sud 

 de I'ile (iable {Jullien). 



Ibid. (p. QQ Sep.), 

 Rhynchopora longirostris, sp. n. 



Not identical with Mucronella tuhulosa, Hincks (see 

 * Annals ' for August 1891, p. 172). 



Ann. cC" Mag. X. Hist. Scr. 6. Vol. ix. 2-4 



