Anthessius — Illg 
359 
most basal elements of ornamentation flat tooth- 
like structures, compound apically and artic- 
ulating with margin of appendage; remainder of 
ornamentation a long row of graduated denticles, 
about 15 of them of conspicuous size. On an- 
terior margin articulated a long lashlike auxil- 
iary seta with outer margin bearing graduated 
row of spinules on proximal third; inner mar- 
gin without spinules. Between apical lash and 
auxiliary seta a subtriangular cuticular piece, 
flat and platelike. 
Maxillule (Fig. 66) of characteristic type of 
the genus, an elongate plate with lobed apex. 
On apex a spine; at midpoint of lateral margin 
a seta. An apical indentation setting off a blunt 
median subapical lobe. Margins of appendage 
much sclerotized. A few spinules on median 
lobe and row of graduated spinules subtending 
apical spine. 
Maxilla ( Fig. 67 ) with very long articulation 
with body, resulting in characteristic basal seg- 
ment, on which articulates flattened apical seg- 
ment, with heavily cuticularized margins. Apex 
produced in sharp angle anteriorly with tooth- 
like expansions of cuticle forming a medial saw- 
edge. Four large teeth formed by flangelike pro- 
trusions of cuticle. Inserted at base of angle of 
curvature of this segment and lying on surface, 
a small, articulated spine. 
Maxilliped ( Fig. 68 ) fairly long, a prominent 
mouthpart, as seen in general habitus of mouth 
area, but with little development of segmenta- 
tion or ornamentation. Three segments sug- 
gested by folds and flexures of integument. Ter- 
minal segment with 2 apical setules. Margins 
cuticularized and produced into 2 spinulelike 
protrusions. 
First legs (Fig. 72) with well-developed 
bimerous protopodites, yoked by substantial in- 
tercoxal plate. Basal width of basipodite less 
than width of distal margin of coxopodite, so 
medial seta of coxopodite inserted on free por- 
tion of margin. Small spinules forming ornamen- 
tation on lateral corner of coxopodite. Coxop- 
odite seta very long, extending rather medially 
and distally, and with its length more than 
width of intercoxal plate. Basipodite with long 
lateral seta proximal to insertion of exopodite 
and with row of cilia on distal margin. Exop- 
odite with slight medial flexure, trimerous. 
Armature: first segment, 1 lateral spine; sec- 
ond segment, 1 lateral spine, 1 medial seta; 
third segment, 3 lateral spines, 1 terminal spine, 
1 terminal seta, 3 medial setae. First segment 
with large spinules on lateral margin, row of 
cilia on medial margin. Proximal 5 spines of 
ramus each outlined with serrate hyaline flange. 
Apical spine with external hyaline flange and 
internal row of cilia. Endopodite flexed medially 
and proximally. Armature: first segment, 1 me- 
dial seta; second segment, 1 medial seta; third 
segment, 1 lateral spine, set in distinct emar- 
gination, 1 lateral seta, 1 apical seta, 3 medial 
setae. Each of 2 basal segments produced at 
distal lateral corner as spinous cuticular process. 
Spine of terminal segment subtended by such 
process, and with outlining hyaline flange. Each 
segment with row of cilia on lateral margin. 
All setae of leg with plumose ciliation. 
Second legs (Fig. 73) with well-developed 
bimerous protopodites yoked by substantial in- 
tercoxal plate. Medial seta of coxopodite on 
medial free portion of border of segment. Seta 
about as long as width of intercoxal plate. A 
row of spinules at distal lateral corner of cox- 
opodite. Basipodite with short lateral seta; 
terminal margin with rows of cilia. Exopodite 
trimerous. Armature: first segment, 1 lateral 
spine; second segment, 1 lateral spine, 1 medial 
seta; third segment, 3 lateral spines, 1 terminal 
spine, 1 terminal seta, 4 medial setae. First seg- 
ment with row of stout spinules on lateral mar- 
gin, cilia on medial margin. Proximal 5 spines 
of ramus each outlined with serrate, hyaline 
flange. Apical spine with external hyaline flange 
and internal row of cilia. Endopodite flexed 
medially and proximally. Armature: first seg- 
ment, 1 medial seta; second segment, 2 medial 
setae; third segment, 2 lateral spines, set in step- 
like emarginations, 1 terminal spine, 3 medial 
Figs. 59—70: Anthessius nortoni, new species. The scales accompanying certain figures represent 0.1 mm. 
Female: 59, habit, dorsal; 60, ventral apical region of cephalosome; 61, structures at genital aperture; 62, 
one side of anal segment showing ornamenting spinules; 63, antenna; 64, oral area; 65, mandible; 66, max- 
illule; 67, maxilla; 68, maxilliped; 69, fifth leg; 70, part of anal segment and caudal ramus. Legend: L, 
labrum; M, mandible; P, maxilliped; U , maxillule; X, maxilla. 
