NO. 1222. ISOPODS OF THE ATLANTIC COAST— RICHARDSON. 551 



Family XIV. ASELLID.E. 



AN.\LYTIC.\I, KEY TO THE (!EXP:R.\ OF .VSETJJD.T;. 



a. ^ran(li))k>H without u ]>;il|). T>ant six jtairs of legH with dactyhif^ Inunguiculate. 



49. MaiicaHellus. 

 d'. [Mandible with a three-jointed palp. Last six pairs of legs uniunguiculate. 

 h. f^yes present. Body oblong, depressed. Head small, narrower and shorter 

 than first thoracic segment. Caudal segment not longer than broad. 



50. AtidluH. 

 }/. Eyes- wanting. Body elongate, narrow. Head large, not narrower than first 

 thoracii' segment, and longer. Caudal segment much longer thau broad. 



51. Ciecidotea. 



49. MANCASELLUS Harger. 



AN.'VLYTICAL KEY TO THE SPECIES OF MANCASELLIIS. 



a. Lateral margins of head entire 121. Mancasellus brachi/ums Harger. 



a^. Lateral margins of the head not entire. External antennje as long or longer than 

 the body 122. 31ancasellus li neat us ( Say ) . 



121. MANCASELLUS BRACHYURUS Harger. 



Mancasellus brachyurus Harger, Am. Jour. Sci., XI (1876), pp. 304, 305. — 

 BovALLius, Bihang till K. Sv. Vet.-Akad. Handl., II, No. 15, 1886, p. 39. 



ITahitat. — McKee's Spring, Lexington, Virginia. 



122. MANCASELLUS LINEATUS (Say). 



Ascllns lineaius Say, Jour. Ac. Nat. Sci. Phila., I, 1818, p. 428. 

 ILihitat. — Soutii Carolina. 



SO. ASELLUS Geoffrey. 



ANALYTICAL KEY TO THE SPECIES OF ASELLUS. 



a. Caudal stylets broad and flattened. Propodus of first pair of legs much enlarged 

 and subglobular, with a prominent acute tooth about or a little aboYe the 

 middle and a lobe bearing one or two acute teeth near the base on its palmar 

 margin 123. Asellus communis Say. 



a,\ Caudal stylets extremely narrow and cylindrical. Propodus of first pair of legs 

 narrow, elongate, without prominent acute tooth on its palmar margin. 



124. Asellus attenuatus Richardson. 



123. ASELLUS COMMUNIS Say. 



Asellus commimis Say, Jour. Ac. Nat. Sci., Phila., I, 1818, j)p. 427, 428. — Smith, 

 Rep. U. S. Fish Com., 1874, p. 657. 



ITahitat. — Schuylkill River, Pennsylvania; Connecticut; Massachu- 

 setts; New York; Indiana; Illinois; Michigan; Mississippi. 



