the shape of broad reflector strips lining the bottom of large eye cups 

 (Scypholanceola). Finally, the eyes may be modified into small pigment 

 spots devoid of receptor elements (some Lanceola) or disappear alto- 

 gether (some Lanceola, Chuneola, Microphasma, some Scinidae, Vibil- 

 ioides, and Vibilia caeca). 



The structure of the head, antennae, and oral appendages is of deci- 

 sive importance in the systematics of Hyperiidea and for separating major 

 taxa within this group: families, subfamilies, and genera. Both pairs of 

 antennae are reduced to some extent — generally to a greater degree in 

 females than in males. The first pair of antennae is attached to the anterior 

 or ventral surface of the head. They generally have a three-articled base 

 and primary flagellum; an accessory flagellum is always absent. The first 

 two basal articles, and sometimes all three (family Scinidae) are often 

 fused. ITie proximal articles of the flagellum, as in gammarideans of the 

 family Lysianassidae, are fused, forming a highly conical or boomerang- 

 like proximal article (males of Platysceloidea). The flagellum varies in 

 17 size; it may be considerably shorter than the head (Microphasmoides, 

 females of Hyperiidae, Platysceloidea) or longer than the pereon and 

 pleon together (some species of Scina). 



The distal articles of the flagellum may be absent (families Scinidae, 

 Paraphronimidae, Cystisomatidae, females of Hyperiidae, Phronimi- 

 dae) or present as two-three rudimentary articles (families Lanceolidae, 

 Mimonectidae, Proscinidae, Archaeoscinidae, Microphasmidae, Vibili- 

 idae, females of Platyscelidae). However, in males of the families Phron- 

 imidae, Hyperiidae, and Dairellidae, the proximal article is small but 

 the distal part of the flagellum is multisegmented, nearly reaching the 

 body length (in sexually mature males of Hyperia, Parathemisto, Phron- 

 imopsis, and others). The conical proximal article of the flagellum is 

 often densely covered with setae (males of Lanceolidae, Phronimidae, 

 Hyperiidae, Platysceloidea, and others), but the thin distal articles of the 

 flagellum, except for apical setae, are unarmed. 



Antennae II are attached to the lower side of the head. Normally, they 

 have a five-articled stalk [peduncle] and a multi-articled flagellum, usually 

 reduced to some degree; however, antennae II may be totally absent (espe- 

 cially often in females). The 2nd article of the peduncle bears a conical 

 antennal gland; in some groups it is reduced but in others well developed 

 and almost as long as all the distal articles of antennae II (Microphasmidae, 

 Chuneolidae). Antennae II are highly developed in males of several gen- 

 era of the family Hyperiidae {Hyperia, Hyperoche, Parathemisto, Bougisia 

 and others), in which they have a whiplike multisegmented flagellum and 

 are not shorter than antennae I. The number of articles in the peduncle 

 of antennae II is usually not more than four and that of the flagellum, 

 2-3. In males of the Platysceloidea, they are five-articled (three articles in 



