V °l889. n '] PROCEEDINGS OF THE NATIONAL MUSEUM. 329 



Family MURIOID^J. 



Subfamily MTTRICINiE. 



Genus MUREX Liiino, 



Murex (Chicoreus) Leeanus sp. uov. 



Plate vii, Fig. 1. 



Shell strong, stout, pale yellowish brown, with three varices to each 

 whorl, and a faint intervarical node between each pair of varices; the 

 varices toward the apex fall slightly short of completing a whole whorl, 

 so that they are slightly spirally arranged; the deficit on the whole shell 

 of six and a half whorls (excluding the nucleus) is about one-quarter of 

 a turn, so that the great varical spines on the spire are not directly 

 over one another; nucleus minute (lost in the specimen); first whorl or 

 two with eight or ten small spiny or scaly nodes; at the third whorl 

 the spines begin to take on the characteristic trialate arrangement ; 

 spiral sculpture of rather fine, rounded threads, almost uniformly dis- 

 tributed, slightly coarser in front of the periphery and on the varices, 

 and in front of the suture for a short distance nearly obsolete; the in- 

 terspaces are narrow grooves, with very rarely an intercalary thread; 

 there are also fine microscopic spiral stria}; this spiral sculpture, with 

 the qualifications noted, covers the whole shell; transverse sculpture 

 of iutervarical nodes obsolete or obscure on the last whorl, growing 

 stronger and sharper toward the apex; apart from the varices the only 

 other sculpture, in a transverse sense, is due to irregularities of growth 

 or faint incremental lines; the varices on the last whorl are slightly 

 elevated, rounded ridges, extending from the suture to the end of the 

 canal ; behind the periphery the whorl is flattened ; at the periphery 

 or shoulder of the whorl each varix is extended in a strong, stout, single 

 hollow spine, rounded behind, deeply narrowly grooved in front, curv- 

 ing slightly upward and more strongly backward toward its distal end; 

 the aperture is ovate, rounded behind, a little pointed in front, with a 

 thin, raised edge, white or waxen internally and without denticulations; 

 the canal is closed, long, stout, obliquely truncate in front, showing two 

 older termini at the left beside the one in actual use. Maximum longi- 

 tude of shell, 70; 'maximum latitude, including spines, <>,">; latitude of 

 aperture, 13.5; longitude of aperture, 20 mm . 



Hab. — Station 2838, off Cerros Island, Lower California, in 44 fath- 

 oms, mud. 



The only species with which this fine Murex need be compared is M. 

 centrifuges Hinds, a member of the same fauna! region, which also was 

 collected near Cape St. Lucas, in 12 to 51 fathoms. The specimens of 

 M. centrifugus hitherto collected have not exceeded .'55""" m total 

 length. The most obvious difference between the young of M. Leeanus 

 and 71/. centrifugus of the same size is seen in the varical processes. 

 In M. Leeanus a section of these processes at any age is oval, with a 



