140 TROPHON. 



last whorl with six squamose revolving lines ; lines of growth 

 membranaceous, croM'ded, nndulated. Length 22, lat. 10*5 mill. 



Polar Sea. 

 T. Maltzani. Kohelt (tig, 301), is an Alaska form in wliieli the 

 varices are nearly entirely suppressed. 



T. MURTCATUS, Mont. PL 31, figs. 308, 311, 311). 



Yellowish or flesli-color, sometimes white (var. aJha). 

 Length, -^^ inch. 



England; Ireland ; Atlantic Coasts of Fh'ance ; Spain ; 



Portugal ; Mediterranean ; 8-150 fathoms. 



The ova-capsules are described by Jetfreys as aliout a line in 

 diameter, with an oval orifice ; they contain a purplish liquor^ 

 together with the fry. The animal is light yellow or whitish. 

 Eaten by fishes — Trigla Gurnardi and Peri^tedion cataphractum. 

 It has also been taken, on a single occasion, from a fish caught 

 on the Massachusetts coast. 



T. Barvicensis, Johnst. PI. 31, fig. 318. 



Shell and animal white. The shell is broader, proportionally, 

 than T. muricatus ; it is also a little more shouldered, and has 

 fewer ribs, which are more laminar and prominent. 



Length, •fi--9 inch. 



North British ; Norway ; Mediterranean ; 8-200 fathoms. 



Creeps like Lachesis, foot upAvards, on the surface of the 

 water. An ova-capsule was found by Mr. Jett'reys in a valve of 

 Leda minuta : it is very thin, semitransparent, and marked with 

 delicate, close-set, microscopic, concentric lines ; orifice oA'al 

 The species bears the Roman name of Berwick-on-Tweed. 



So far the Mediterraneaji specimens Iima'c only been obtained 

 at considerable depths. 



T. Clathratus, Linn. Pi. 31, figs. 312, 314, 31 (i, 31 T, 322, 325. 

 Most authors separate this into tAvo species, distinguished by 

 size and number of ribs. T. trimcatua, Striim. (fig 325), is about 

 •6 inch long, with twent}- ribs on the body-Avhorl ; whilst T. 

 clathratus, L. (fig. 312), has fourteen ribs when the same size, 

 and grows, moreover, to much greater dimensions. I have no 

 doubt that the British specimens are all small and correspond 



