MUSEUM OF COMPARATIVE ZOOLOGY. 219 



greatest depth. The specimen figured (max. Ion. 20.0 mm.) is young, and has 

 the expansions of the periphery much turned up. The older ones, which reach 

 a length twice as great, or more, have the flat spines nearly horizontal. There 

 may he ten or twelve of them on the last whorl. After careful comparisons, I 

 conclude that, though it passes through a series of variations parallel to those 

 of 0. bracteata, it is sufficiently distinct from it to be easily recognized as differ- 

 ent, when in good condition. It has the typical or spiny form, with flat ex- 

 pansions; another (var. spinosa) in which the spines are thorn-like and slender; 

 a form (var. fusiformis) in which there are no spines, yet there are no trans- 

 verse ribs; and finally a form (var. Lintoni Verrill) in which numerous rounded 

 transverse ribs of greater or less strength appear under the limose spiral ridges. 

 The last was very naturally described as a Trophon. There may be between 

 the above-mentioned varieties almost any graduation or interchange of charac- 

 ters, but usually the vigor which in one case expends itself in the formation of 

 flat spines, in their absence is more or less devoted to the formation of trans- 

 verse ribs. 



Coralliophila bracteata Beocchi. 

 C. bracteata Tryon, Man., II. p. 210, pi. lxvi. figs. 378-380, 384, 386, 1880. 



A specimen which seems to belong to this species as existing in the Jeffreys 

 collection, and to be distinct from the preceding, was collected by the U. S. 

 Fish Commission, in 17 fms., near Cape Fear, North Carolina; another at Key 

 West, in 45 fms. The first belonged to the variety C. lamellosa Jan, the 

 second to the variety C. lacerata Deshayes. The former was adult, the latter 

 quite young. 



Coralliophila galea Chemnitz. 



Coralliophila galea Tryon, Man., p. 207, pi. Ixv. figs. 362, 363, 364, 1880. 

 C. abbieviata ~La.m.,Jide Tryon. 



Lamarck's name should probably take precedence, but I have not had time 

 to devote to the synonymy. 



This species has a nearly world-wide distribution in the tropics, and in our 

 region extends throughout the Antilles and northward along the coast from 

 Florida to Cape Hatteras. It is generally white, but specimens with a purple 

 mouth are not rare in the Windward Islands. The young are known under 

 many names, and generally are sharply keeled at the shoulder and shortly 

 acutely conical at both ends, having a very different aspect from the rounded 

 adults. The Fish Commission has dredged this species in 15-100 fms., living 

 among coral. The shore specimens are carried there by Paguri; I do not know 

 of a single specimen ever collected above low- water mark in a living state. 



