ACA.] 



CRUSTACEA. 



525 



SUBCLASS PODOPTHALMATA. 



ORDER PHYLLOCARIDA. 

 FAMILY CERATIOCARID^I. Ceratiocaris, Colpocaris, Echinoearis, Elymocaris, 



Ribeiria (?), Solenocaris, Tropidocaris. 

 FAMILY DISCINOCARID.E. Dipterocaris, Spathiocaris. 

 FAMILY PINACARID^. Dithyrocaris, Mesothyra. 

 FAMILY PROTOCARID^E. Protocaris. 

 FAMILY RACHURID^E. Rachura. 

 FAMILY RHINOOARID^;. Rhinocaris. 



ORDER DECAPODA. 



FAMILY ANTHRACARID^. Anthrapalsemon. 

 FAMILY CARIDID.E. Palseopalsemon. 

 FAMILY PAL^OCARID^E. Gampsonyx, Palseocaris. 



ORDER TETRADECAPODA. 

 FAMILY ARCH^OCARID^E. Archseocaris. 



ACANTHOT ELSON, 



Meek & Wor- 

 then , 1 860, 

 Proc. Acad. 

 Nat. Sci., p. 47. 

 [Ety. akantha, 

 spine ; telson, 

 end.] Superior 

 antenna? as 

 long as the in- 

 ferior, flagella 

 longer than the 

 peduncles; 

 head about the 

 length of the 

 two anterior 



thoracic segments; thoracic and 

 abdominal segments about the 

 same length ; anterior thoracic legs 

 longer than the others ; telson sim- 

 ple, long, spine-like, laterally com- 

 pressed ; stylets with second segments longer than 

 first, and similar to the telson. Type A. stimpsoni. 

 eveni, Meek & Worthen, 1868, Am. Jour. Sci., vol. 



FIG. 947. Acanthotelson eveni. A, dorsal view; st, stylet; t, 

 telson ; B, side view; a aud x, antennae; /, anterior leg; 

 C, enlarged stylet. 



s t i m p s o n i. 

 Dorsal view - 



Fio. 918. Acanthotelson event. 

 Enlarged ; H, anterior legs and 



antennae; 8, punctures left by Kio. 950. Acanthotelson stimpsoiii. Enlarged 3 diam.; 

 spines on the lower side. *, a protuberance that may be an eye. 



Acantlioloma, syn. for Acidaspis. I 46, p. 28, and Geo. Sur. 111., vol. 3, p. 



spinosa, syn. for Acidaspis tuberculata. | 551, Coal Meas. 



