DISCINIDA. 337 
? Cuetopes, Davidson, King, 1874. 
Distr.— U. Silurian; Gotland, Sweden. C. Bergmavi, D. 
and King. 
Notwithstanding remarkable points of resemblance, it is our 
opinion that it is not a palliobranch; on the contrary, we are 
strongly inclined to the belief that it belongs to a section of the 
celenterates, represented by Calceola and Gonicphyllum.— 
DAVIDSON AND KING. 
Possibly a coral. Looks like the internal fulcrum of Zirphzea 
(Leuconyx, H. Adams).—DaAtL. 
Linautops, Hall, 1871. 
Dist — i. Silur.; N. Am. 6. Whitfield, Hall. 
Founded upon a cast of the interior of a single valve of a 
Lingula-shaped shell, but differing from that genus in its inte- 
rior impressions. The most striking features are: first, a 
posterior, semicircular, broad zone, with an inner sinused bor- 
der; second, an arched fillet situated below the hinge and on 
the zone, the crescent characterizing the Trimerellids; third, 
a central space marked with sears (the apophysary system ); fourth, 
linear impressions occurring in the anterior half of the fossil 
median plate, and pair of primary vessels belonging to the 
brachioceele. 
Famity DISCINIDA. 
Shell attached by a pedicel, passing through a foramen in the 
ventral valve; valves not articulated ; minutely punctate. 
Animal with a highly vascular mantle, fringed with long, 
horny setz; oral arms curved backwards, returning upon them- 
selves, and ending in small spires directed downwards, towards 
the ventral valve. 
Disctna, Lamarck, 1819. 
syn. — Orbicula, Sby. (mot Cuvier), 1830. Schizotreta, 
Kutorga, 1848. 
Distr.—10 sp. West Africa, W. Indies, Malacca, Peru and 
Panama. Fossil, 64 sp. Silurian—; Europe, United States, 
Falkland Islands. JD. striata, Schum. 
Shell orbicular, horny; upper valve limpet-like, smooth or 
concentrically lamellose, apex behind the centre; lower valve 
flat or conical, with a sunk and perforated disk on the posterior 
side, from which interiorly extends a furrow; interior polished 
“nimal transparent; mantle-lobes distinct all round; labial 
folds united, not extensile ; alimentary canal simple, bent upon 
itself ventrally, and terminating between the mantle-lobes on 
the right side. There are four distinct adductor muscles, as in 
Crania; and three pair of adjuster muscles for keeping the 
