REVISION OF RECENT BAIRDIIDAE 



47 



Figure 21. — Paranesidea arostrata (Kornicker), paratype male specimen 122C-1. 



A, Third thoracic leg; B, second thoracic leg; C, first thoracic leg; D, antennal claws; 

 E, copulatory organ and furca. A-C, X 152; D,E, X 301. 



Type locality. — Nosy Be, Madagascar, sample 446 (washings of 

 a green alga at low tide level of the beach at Antsakoabe). 



Diagnosis. — Carapace rather compressed and especially so mar- 

 ginally, with the break in slope between marginal and medial surface 

 areas visible as a subtly sulcate shadow, greatest height located 

 slightly behind midlength, greatest thickness median, posterior end 

 slightly caudate. 



Copulatory organ with oblong median lobe, subquadr angular 

 termhial lobe bearing ventrodistal finger-like projection; copulatory 

 tube curved in shallow sigmoid fashion, apparently penetrating 

 distal lobe. 



Material. — Nosy Be; 59 living specimens, 116 subfossil specimens. 



Habitat. — Nosy Be; common on many varieties of calcareous 

 and noncalcareous algae near low tide level on the back-reef platform, 

 also on coralline detritus. 



