514 U.S. NATIONAL MUSEUM BULLETIN 271 



EYES 



Composition: 



Presence or absence (careful examination required because eyes often lose 

 pigment in preservative). 



Paired ommatidial mass below cephalic cuticle (common). 



CuHcular lenses in lateral pairs (Ampeliscidae almost exclusively). Occasionally 

 lenses occupy anterior surface of head. 



Diffused pigment or stain. 



Quadrigeyninous lenticular bodies (example, Argissidae). 



Bright pigmentary masses enveloping brain (especially Ampeliscidae). 

 Shape: ovoid, flask-like, reniform. 

 Position : 



Near lateral cephalic surface. 



In lateral lobes. 



In rostrum (especially Oedicerotidae). 



Dorsally confluent (especially Oedicerotidae). 



Accessory detached ommatidia (pattern often confused by preservational 

 accidents) . 



Occupying cephalic extent almost fully (Hyperiopsidae). 



ANTENNA 1 



Length : 



As percent of total body (front of head to base of telson ( %). 



In relation to antenna 2 and to its peduncle ( %). 

 Flagellum: 



Proportion to peduncle ( %). 



Elongation of basal article (often conjoint, composed of incompletely seg- 

 mented articles). 



Proportion to peduncular article 3, especially when latter elongated ( %). 



Number of articles: 0, 1, 2, 3, 4, 5, 6-10, 11-15, 16+. 

 Peduncle: Proportion to head. 



Relative lengths of all three articles (value of 100 assigned to length of article 

 1): 1 = 100%; 2 = ( %);3 = ( %). 



Ornamentation on any article, all sides. 



Distinctive spines or setal bundles. 



Possible geniculation between articles (example, several Haustoriidae). 

 Accessory flagellum (attached to article 3 of peduncle, medial) : 



Number of articles: 0, 1, 2, 3, 4, 5-10, 11 + . 



A fused scale. 



Special shape. 



Elongation of basal article. 

 Accessory organs: 



Calceoli. 



Aesthetascs, if especially enlarged or in dense bundles. 



ANTENNA 2 



Length as percent of body length (including head) ( %). 

 Peduncle: proportion to head ( %). 



Relative proportions of articles: 4 = 100%; 5 = ( %). 

 Tumidity of articles 3, J^, or 5; article 1 large and subspherical. 

 Gland cone and/or ensiform process on articles 2 and 1 ; extreme enlargement 

 and shape. (Ensiform process genericallj' important primarily in Phoxo- 

 cephalidae. Gland cone often medial and hidden from lateral view.) 



