128 MEMOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 
Explanation of Plate Il. 
Fig. 1. Acanthotelson stimpsoni M. & W. : 
Fig. 2. Acanthotelson stimpsoni M. & W., reverse of fig. L. 
Fig. 3. Acanthotelson stimpsoni M. & W. 
Fig. 4. Acanthotelson ? mggister Pack. 
Vig. 5. Acanthotelson ? magister Pack., reverse of fig. 4. 
From photographs taken by Mr. Robert L. P. Mason. 
Note on an additional specimen.—Since this memoir was sent to the printer I have received a larger specimen from 
Mr. Lacoe, labelled ‘* Braidwood, Ill, Q'”, which, exclusive of the antenne and telson, measures about 82", There 
are traces of four pairs of thoracic feet which are long and slender and bent backwards from the head, reminding us 
of the four hinder legs of an ordinary shrimp seen from one side. There are traces of the antenna, better preserved 
than in the original specimen. There appear to be a pair of large antenni, the scape composed of three large joints, 
the second and third smaller and together equalling in length the basal joint; these antenne appear each to bear a 
large antennal scale, resembling those of the Macrura, and reaching as far as the middle of the third antennal joint. 
The characters shown by this specimen lead me to refer if to a genus distinet from Acanthotelson, for which the 
the name Belotelson (the entire name, Belotelson magister) is proposed, Additional] specimens are much desired to 
complete our knowledge of its affinities. 
