18S7.] PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 563 



outline, smallest at the distal end, which is somewhat indented on the 

 outer side, and with four stout, tapering spines, three at the tip, and a 

 single one, the Largest, just below the middle on the outer margin. 

 The iuntr ramus is located close by the outer one, and is very broad 

 and divided distally into two rounded lobes, of which the outer is much 

 the wider. The outer ramus of the fourth jjair is similar to that of 

 the third pair, but smaller, with a spine on the outer margin and appar- 

 ently four spines at the distal end, of which only two were preserved 

 in the specimen figured. The inner ramus is distant from the outer 

 one, is very short and broad, and divided into two subequal, rounded, 

 overlapping lobes. 



The above descriptions of the swimming feet and the figures to which 

 they refer are taken from var. StimpsouL The typical form presents only 

 slight variations, mostly limited to the inner rami of the second, third, 

 and fourth pair of feet. In the second pair the distal joint of the inner 

 ramus is slightly more elongate and ovate in shape. The inner lobe of 

 the corresponding ramus of the third pair is much elongate, with sub- 

 parallel sides, and is curved strongly inward toward the tip. The cor- 

 responding lobe of the fourth i)air of feet is also somewhat longer than 

 the outer lobe, and four spines are preserved on the distal end of the 

 outer ramus in all the specimens examined. 



The typical form has been obtained by the TJ. S. Fish Commission 

 from four species offish, as follows: The dusky shark, Carcharlnus 

 obscuriis, collected in Vineyard Sound, Massachusetts, 1887 (12085), and at 

 Noank, Conn., 1874: (8181) ; the blue shark, Garcharinns Milberti, Vine- 

 yard Sound, 1884 (8180); the shovel-head shark, Eenlccps f lb uro, month 

 of St. Mary's River, Florida, 1881 (8182) ; and the sharp-nosed shark, 

 Scolioclon tcrrcc-novcv, Peusacola, Fla., Silas Stearns (G0S5). The single 

 specimen of the var. Stimpsoni (4114) was collected at Great Egg Har- 

 bor, New Jersey, by Dr. William Stirapsou j its host is unknown. 



Lernanthropiis Brevoortiae Eathbuu, new species. 

 (Plate XXX, Figs. 7, 8; Plates XXXI, XXXII). 



This species is above medium size, and is readily distinguished by the 

 shape and proportions of the thoracic feet of the third and fourth pairs, 

 which are very greatly developed, the latter being exceedingly long, 

 broad, foliaceous. The following description, excepting in so far as it 

 applies to the microscopic appendages, has been drawn up mainly from 

 living specimens. 



The cephalothorax is oblong in outline, as viewed from above, the 

 length, however, being only slightly greater than the width. The an- 

 terior margin is broad, slightly convex, and rounded at the corners; 

 the sides diverge gradually and may be slightly convex, slightly con- 

 cave, or straight along the middle, but at the hinder end, where the 

 width is greatest, they are always convex and well rounded, as is also 



