132 Mr. L. A. Bonadaile on a 



Body fl<^xil)le, covered witli a stout cuticle, divided into from 

 200 to 300 equal segments, which are often (? always) pa])il- 

 latc, but Ijoar no a|)|)end:vcres or visihle setaj. Gut simple, 

 straight, ai)parently slio;htly segmented (traced from within 

 25 mm. of one end to within 20 mm. of the other end in an 

 individual 69 mm. long). 



The species heroin discussed are : — 



P. magmis, Miller & Faber. Upper Ordovician, Fultou Formation, 

 Cincinnati. 



P. covingtonensisy Uh'icb (genotype). Upper Ordovician, Eden Forma- 

 tion, Kentucky. 



P. ornatus, Ulrich. Upper Ordovician, Eden Formation, Kentucky. 



P. tenuis, Ulricb. „ „ „ „ „ 



P.simi)le.v,\j\nch. „ „ „ „ „ 



P. lattis, sp. n. Upper Silurian, Lower Ludlow, Ilerefordsbire. 



P. carbouarius (Kustn, sub Pronaiditea). Upper Carboniferous, Noegge- 

 ratliia beds, Bobemia. 



XIII. — On a new Commensal Prawn. 

 By L. A. BORKADAILE, M.A. 



A .SHORT time ago I received, hy the kindness of I\Ir. W. L. 

 Schmitt, of the United States National Museum, four speci- 

 mens, one an ovigerous female, of a new member of the 

 ubiquitous subfamily Pontoniina?. They were collected at 

 Beaufort, N.C, whore they are said to be abundant on the 

 *' .sea-feathers" close to the Island. The following diagnosis 

 sets forth the distinguishing features of tiio species to which 

 they belong : — 



Periclimenes beaufortensisy sp. n. 



Diafjnosis. — Body rather stout, not compressed ; rostrum 

 about I length of carapace, almost or quite reaching end of 

 first joint of antennular stalk, straight, slender, very sharp- 

 ])ointed, without teeth, but with a low crest above iu its 

 hinder part ; antennal, but not hepatic or supraorbital, spines 

 ])resent ; cornea subhemi-spherical, of moderate size ; antennule 

 with well-d(;veloped spines at base and at end of fir.«t 

 joint, third joint about one-thiid length of first, second about 

 two-thirds length ol third, inner flagcllum about half as long 



