TEREBRATULID. 309 
10-120 fathoms. Fossil, 22 sp. Jurassic—; United States, 
Europe. 7. caput-serpentis, Linn. (cxxxiv, 14—16). 
Shell finely dichotomously striated, auriculate, deltidiam 
usually rudimental; foramen incomplete; loop short, rendered 
annular in the adult by the union of the oral processes. 
WALDHEIMIA, King, 1849, 
Syn.—Magellania, Bayle, 1880. 
Distr.—9 sp. Norway, W. Indies, Java, Australia, California, 
Cape Horn; low-water—100 fathoms. Fossil, 90 sp. Carb.—; 
South America, Europe. W. Australis, Quoy (exxxiv, 1, 17-19). 
W. flavescens, Lam. (exxxiv, 20—22). 
Shell smooth or plaited, dorsal valve frequently impressed ; 
foramen complete; loop elongated and reflected; septum of 
smaller valve elongated. 
WALDHEIMIA (restricted), Dall, 1871. Shell globose, neural 
beak more or less produced; foramen complete or incomplete ; 
deltidia separated or united; pedunculated ; a ridge or septum 
usually existing in the hemal valve. Mouth behind the brachia, 
which consist of two lateral lobes and a central spiral lobe. 
W. flavescens, Lam. 
EUDESIA, King, 1850. Shell swollen, oval; valves sharply 
plaited ; beak-opening round, large; median septum and tooth- 
plates developed. W. Grayi, Davidson, and 6 fossil sp. 
MACANDREVIA, King, 1859. (? Gwynia, King, 1859. Neothyris 
and Plesiothyris, Douvillé, 1879.) Smooth, longitudinally oval, 
inequivalve, the condyle valve being the largest; foramen emar- 
ginated by the deltidial fissure; umbonal cavity of large valve 
furnished with two muscular fuleral plates passing somewhat 
perpendicularly from the dental protuberances to the surface of 
the valve; umbonal cavity of opposite valve also furnished with 
similarly directed plates; cardinal muscular fulcrum excavated 
in the substance of the hinge; loop long, strongly recurved, and 
extending in front of the centre of the valve. Includes the 
recent W. cranium, Miull., which is the type, and a number of 
fossil forms. 
ZEILLERTA, Bayle, 1879. (Macandrewia, Schloen. Orthotoma, 
Quenst., 1871.) Differs from Waldheimia in the presence of two 
rostral partitions upon the hinge. Jurassic—Tertiary; Europe. 
W. lagenalis, Schloth. (exxxiv, 23). 
AULACOTHYRIS, Douvillé, 1879. Apophyses, rostral partitions 
and septum asin Zeilleria; foramen generally small and oblong. 
Distinguished by its exterior form, the smaller valve having a 
median furrow. Triassic, Jurassic, Cretaceous. W. resupinata, 
Sowb. (exxxv, 24). 
ANTIPTYCHINA, Zittel, 1880. Large valve swollen in the middle, 
with a strong fold on either side; small valve usually somewhat 
