592 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 55. 



PAEON FEROX, new species. 



Plate 56 ; plate 57, figs. 60, 61, 63, 64, 66. 



Host and record of specimens. — Twelve females, two of them with 

 attached males, were obtained by the author from the gill cavity of 

 the sharp-nosed shark, Scoliodon terrae novae., in July, 1905, at Beau- 

 fort, North Carolina. These have been divided into three lots — the 

 first, a single female with ^^^ strings, is made the type of the new 

 species with Cat. No. 47824, U.S.N.M. Four other females become 

 paratypes with Cat. No. 47825, U.S.N.M., and the remaining seven 

 are also made paratypes with Cat. No. 47826, U.S.N.M. 



External specific characters of female. — Cephalothorax enlarged 

 transversely by a pair of hemispherical lateral processes into a 

 tolerably regular ellipsoid, upon the anterior and ventral surfaces 

 of which are several pairs of knobs or protuberances. One pair are 

 doi'soventrally elliptical and extend across the anterior margin so 

 as to be visible in a dorsal as well as a ventral view. Their adjacent 

 surfaces meet on the midline and are flattened together ; their dorsal 

 surfaces are about on a level with the dorsal surface of the head, but 

 ventrally they project considerably and conceal the mouth tube. A 

 little behind them on the ventral surface is a second pair, diagonally 

 elliptical, with their long diameters at right angles to each other and 

 at an angle of 45° with the axis of the head. Their outer ends are 

 opposite the outer margins of the first pair and reach laterally a 

 little beyond them. Their posterior margins are concave and at 

 about the center of each, on the dorsal surface between the knob and 

 the head itself, lies a slender finger-like protuberance, jointed near its 

 base and divided at the tip, and looking much like a misplaced 

 appendage. It contains what appear to be muscles and might easily 

 have migrated to its present position during the outgrowth of the 

 knobs. 



On the anterior margin of the head between the bases of the first 

 pair of knobs are the proboscis and mouth parts. The mouth tube 

 is conical and protrusible, with well-defined upper and under lips 

 like those in the male, and carries on either side a biramose maxilla. 

 Each maxilla is made up of a short basal joint, widened dorso ven- 

 trally, and two rami. The endopod (dorsal ramus) is one- jointed 

 and club-shaped, bluntly rounded at the larger distal end with a 

 spine on its outer surface; the exopod is two-jointed, the terminal 

 joint ending in a long ventral and a short dorsal spine. Just behind 

 the mouth tube on the ventral surface of the head and in front of the 

 oblique processes are the second maxillae. Each is stout, one-jointed, 

 and ends in a strong claw, bent into a half circle and armed at its 

 base on the ventral surface with a slender acuminate spine. The two 

 are inclined toward each other so that their claws meet on the median 



