224 TURRITELLIDA. 
GYROTROPIS, Gabb. Cretaceous; North Carolina. Shell thin, 
resembling Trichotropis in form; spire elevated; umbilicus 
widely open, funnel-shaped; last whorl angulated above and 
below the periphery; covered with very thin foliated longi- 
tudinal varices. G. squamosus, Gabb. 
Famity TURRITELLID 4. 
Rostrum short, broad ; tentacles long and subulate, the eyes 
slightly prominent on their external bases. Mantle with a fringed 
margin, obscurely siphonated at the right side; branchial plume 
single, very long. Foot very short, truncate in front, rounded 
behind, groov ed beneath ; ; operculigerous lobe simple. 
Shell spiral, not umbilicated, Spire very long, of numerous 
whorls, with revolving striz or ¢ carinations. Opereulum corneous, 
multispiral. 
TURRITELLA, Lam. 
Screw-shell. Htym.—Diminutive of turris, a tower. 
Syn.—Turris, Humphrey. Xylohelix, Chemn. 
Distr.—73 sp. World-wide. Ranging from the Laminarian 
Zone to 100 fathoms. West Indies, United States, Britain 
(1 sp.\, Iceland, Mediterranean, West Africa, China, Australia, 
West America. Fossil, 172 sp. Triassic—; Britain, etc., N. and 
S. America, Australia, Java. TZ. terebra, Linn. (xvii, 55). 
Shell elongated, many-whorled, whorls rounded with revolving 
striz ; aperture rounded. Operculum many-whorled, with a fim- 
briated margin. The shells are usually brown, with red-brown 
spots or flames. 
TURRITELLOPSIS, Sars. Shell like Turritella, but the lingual 
dentition differs. A boreal group, doubtfully distinct, 7. acicula, 
Stimpson (lxvii, 56). 
HAUSTATOR, Montfort. Whorls flattened, mouth subquadran- 
gular, outer lip sinuous. 7’. goniostoma, Val. (1xvii, 57). 
TORCULA, Gray. Shell turriculated, usually white or horn- 
color, without markings; whorls subangular, with a median 
excavation; aperture subquadrangular, the outer lip with a 
slight median sinus. 7. cochlea, Reeve (1xvii, 58). 
ZARIA, Gray. Shell turriculated, without color-markings, 
whorls carinated ; aperture subquadrangular, outer lip simple. 
T. duplicata, Linn. (1xvii, 59). 
MESALIA, Gray. Shell turriculated, of numerous whorls; aper- 
ture oval, subcircular, slightly produced, with sinnous and 
reflected anterior margin ; inner lip a little twisted and flattened, 
outer lip thin, sinuous posteriorly. TJ. melanoides, Reeve 
(xvii, 60 . 
EGLISIA, Gray. Whorls rounded, with profound sutures ; aper- 
ture moan ded rather small, inner lip flattened, callous, angular, 
