356 
PACIFIC SCIENCE, Vol. XIV, October I960 
Figs. 48-58: Anthessius lighti . new species. The scales accompanying certain figures represent 0.1 mm. 
Male: 48, habit, dorsal; 49, habit, lateral; 50, antennule; 51, antenna; 52, mandible; 53, maxillule; 54, max- 
illa; 55, maxilliped; 56, fifth leg; 57, sixth leg; 58, caudal ramus. 
spine, 1 apical spine, 1 apical seta, 3 medial 
setae, apical spine representing a seta of the 
female appendage. Leg 2 (Fig. 45), leg 3 (Fig. 
46), leg 4 (Fig. 47) in general aspect and 
ornamentation essentially similar to female. 
Fifth leg (Fig. 56) very similar to that of 
female in general structure and ornamentation. 
Shorter in proportion to width, length equalling 
about 3 times greatest width. 
Sixth legs (Fig. 57) ventrolateral on genital 
segment, involved in very complicated manner 
with structure of reproductive opening. Most 
obviously representative of appendage a small 
prominence bearing 2 setae, the more medial 
with an articulating base. 
Caudal rami (Fig. 58) with no striking dif- 
ferences from those of female. 
REMARKS: This species is named for S. F. 
Light. The species is distinguished from others 
of the genus in the key above. Some of its dis- 
tinctive features may turn out to occur in other 
species when more anatomical details are known 
in the genus. The complement of aesthetes on 
the antennule of the male does not occur in 
A. nortoni and A. fit chi, also West Coast forms, 
but is found in A . arenicolus and A. teissieri 
of Europe. The accessory protuberances of the 
fourth pedigerous segment have not so far been 
reported from any other species. 
