132 Mr. L. A. Borradaile on a 
Body flexible, covered with a stout cuticle, divided into from 
200 to 300 equal segments, which are often (? always) papil- 
late, but bear no appendages or visible sete. Gut simple, 
straight, apparently slightly segmented (traced from within 
2-5 mm. of one end to within 20 mm. of the other end in an ~ 
individual 69 mm. long). 
The species herein discussed are :— 
P. magnus, Miller & Faber. Upper Ordovician, Fulton Formation, 
Cincinnati. : 
P. covingtonensis, Ulrich (genotype). Upper Ordovician, Eden Forma- 
tion, Kentucky. 
P. ornatus, Ulrich. Upper Ordovician, Eden Formation, Kentucky. 
P. tenuis, Ulrich. % 5 oS 5 a 
P. simplex, Ulrich. 5 ‘ E. 5 ay 
P. latus, sp.u. Upper Silurian, Lower Ludlow, Herefordshire. 
P. carbonarius (Kuta, sub Pronaidites). Upper Carboniferous, Noegge- 
rathia beds, Bohemia. 
XIIT.—On a new Commensal Prawn. 
By L. A. BorrapatLe, M.A. 
A sHortT time ago I received, by the kindness of Mr. W. L. 
Schmitt, of the United States National Mnseum, four speci- 
mens, one an ovigerous female, of a new member of the 
ubiquitous subfamily Pontoniine. They were collected at 
Beaufort, N.C., where they are said to be abundant on the 
“ sea-feathers ” close to the Island. The following diagnosis 
sets forth the distinguishing features of the species to which 
they belong :— 
Periclimenes beaufortensis, sp. n. 
Diagnosis.—Body rather stout, not compressed ; rostrum 
about 3 length of carapace, almost or quite reaching end of 
first joint of antennular stalk, straight, slender, very sharp- 
pointed, without teeth, but with a low crest above in its 
hinder part ; antennal, but not hepatic or supraorbital, spines 
present ; cornea subhemispherical, of moderate size; antennule 
with well-developed spines at base and at end of first 
joint, third joint about one-third length of first, second about 
two-thirds length of third, inner flagellum about half as long 
