J/ 



( iLYi'TiDo'iEA Licin KXSTEiN'ir, Krauss. 



Plate io, 



1843- Idolca lichtciistcinii. Kraiiss, Die siidafrikanischen Cru>- 



taceen, p. 62, pi. 4, fig. 4- 

 1881. Idotca lAcktciistiinii, Miers, Jouiii. Linn- Soc. Londoiv 



vol. 16, p. 64. 



The front of the hcaJ is trisimiate, the median notch small and 

 overhung by a large^ blunt-endcd^ horizontal process of the dorsal 

 carina, the lateral angles prciduced into blunt points directed 

 slightly outwards in advance of the small, black, dorso-lateral, 

 triangularly-rounded eyes, behind which the lateral margins con- 

 verge to the faintly-concave hind border- The first perseon seg- 

 mentisshortintheinidclle,butwiththesidesreaching loi u.trdio 

 the eyes, fianking the head with broadly rounded plates, of which, 

 however, the inner and the hinder margins are flattened. Of the 

 six follownig segments the side-plates are a 1 distinct, in shape 

 passing from oval to sub- quadrate, not produced backward, but 

 matching the length cf the segment, which is least in the seventh^ 

 and greatest in the b^^cond ana th!rcl,the latter with us bu.f platt ■- 

 presenting the greatest breadth. The pleon has a length equal 

 to the first three segments ( f the peneon, the breadth at the base 

 being not much less than the length, and nearly two and a half 

 times the width of the apex, which is shallowly enic rginate with 

 rounded corners- The three pairs of sutures are dorsally succes- 

 sively shorter; ventrally they are very distinct. A nJ.edian carina 

 extends from the cephalic process on to the pleon, where it loses 

 the rather moderate acutenes-s of its earlier portion, and near the 

 middle of the segment b'furcates, l)eing vcr) faintly continueel to 

 each apical angle- 

 First antenna: — The flrst joint is deeply cut into several un- 

 equal lobes, among which is implanted the narrow stalk of the 

 second joint; this in turn is divided into lobes at its wideneel 

 distal extremity, receiving the shorter third joint, which also 

 forms a little cup for the narrow base of the flagellum. The latter 

 has the shape of a bladebonc, and has Ts cf nvex n-largin closely 

 set With fourteen .^emi-circular lobes, from each of which projects 

 a pair of hyaline sensory fi'aments and two setules, or perhaps 

 from the last two semi-circles there may be oilv one filament 

 apiece. It is possible that thise na ginal divisions with their 

 apparatus indicate a coalescence of many articulations to form 

 this peculiarly shaped one-jointed t'agellum- 



Second antennae— The first jomt short: the second much wider, 

 cut into deep lobes which encircle the third joint, this also beings 

 wide and lobed. but less stn ugly than the preceding, the fourth 

 joint oblong, a little longer than wide, the fifth abruptly narrower, 

 considerabiv lono-cr ; the flaQvlluni longer than the i^.cdunclc. con- 



