22 Arachn. 
X. Arachnida. 
[1921] 
Hydrachnidae. 
Borner 15 ; Yiets 114, 115, 116. 
Acercus bullatus p. 17 text-figs., 
Viets 114. 
Arrhenurus miilleri spatiosus var. n. 
Escherhausen p. 19, sp. ? p. 20, text- 
figs., Viets Arch. Natg. Berlin 83 A 
Hft. 3 ; A. cylindratus p. 172, com- 
paclus p. 173, telracyphus p. 174, 
interruptus sp. n. Braunschweig p. 
176, sp. ? p. 178 text-figs., Viets 
Arch. Natg. Berlin 83 A Hft. 6. 
Eylais infundibulifera acuta p. 157, 
infundibulifera meridionalis p. 158, 
rimosa p. 159, bisinuosa nodifrons 
var. n. Braunschweig p. 160, Jciihnei 
sp. n. Braunschweig p. 162, text-figs, 
all spp., Viets Arch. Natg. Berlin 83 A 
Hft. 6. 
Hispidosperchon hystrix sp. n. 
Bohemia p. 299 text-fig., Komarek 
Arch. Hydrobiol. Stuttgart 13. 
IJydrarachna bivirgvlala p. 167, 
papiliigera sp. n. Braunschweig p. 168, 
text-figs., Viets Arch. Natg. Berlin 
83 A Hft. 6. 
Ilydryphantes ruber tenuipalpis p. 
166 text-figs., Viets 115. 
Lebertia ( Pilolebertia ) violacea sp. n. 
Westphalia p. 286 pi. iii, Viets Arch. 
Hydrobiol., Stuttgart 13. 
Megapus tenuitarsus sp. n. Bohemia 
p. 301 text-fig., Komarek Arch. Hydro- 
biol. Stuttgart 13. — M. octoporus p. 290 
pi. iii, Viets 113. — M. tuberosus sp. n. 
Escherhausen p. 14 text-figs., Viets 
Arch. Natg. Berlin 83 A Hft. 3. 
Sperchon plumifer var westfalica 
var. n. Westphalia p. 283 ,-glandulosus 
p. 285, papillosa p. 293 pi. iii, Viets 
Arch. Hydrobiol. Stuttgart 13; S. 
denticulatus p. 11 text-fig., compactilis 
discrepans var. n. Escherhausen p. 11 
text-figs., Viets Arch. Natg. Berlin 
83 A Hft. 3. — S. elegans sigthori var. n. 
Braunschweig p. 163, Viets Arch. 
Natg. Berlin 83 A Hft. 6. 
Thyas panissoides sp. n. Bohemia 
p. 304 text-fig., Komarek Arch. Hydro- 
biol. Stuttgart 13. 
Sarcoptidae. 
Stekhoven, 99 ; key to genera, 
pis. ix-xi, Newstead & Morris, 79. 
Alloptes longirostris sp. n. Heligoland 
p. 63 text-fig., Vitzthum Arch. Natg. 
Berlin 87 A Hft. 4. 
Analges vide Analgopsis. 
Analgopsis gen. n. for Analges 
passerinus p. 4, Trouessart & Berlese 
R edial4. 
Berlesella gen. n. (near Mesalges), 
alata sp. n. Borneo p. 4, Trouessart & 
Berlese t.c. 
Caparinia tripilis p. 38 text-fig., 
Vitzthum 117. 
Ingrassia oceanica Heligoland p. 58 
text-figs., Vitzthum 120. 
Lislrophorus frontalis , argenlinus spp. 
n. Argentine p. 366 text-figs., Hirst 
Proc. Zool. Soc. London 1921. 
Nycteridocoptes pteropi sp. n. Africa 
p. 760, Rodhain & Gedoelst C. R. soc. 
biol. Paris 84 ; p. 758, Rodhain 92. 
Plesialges gen. n. (near Analges 
chelopus), mimus sp. n. Australia p. 4, 
Trouessart & Berlese Rodia 14. 
Psoroples nalalensis p. 39, Hirst 52 ; 
P. nalalensis , communis p. 232 figs., 
Hirst 53 
Pterodectes pelagicus sp. n. Heligo- 
land p. 66 text-fig., Vitzthum t.c. 
Rivoltasia quadrata p. 45, Vitzthum 
119. 
Sarcoptes scabei var. equi p. 114, 
var. hominis p. 146, var. scabiei-crustosae 
p. 149, text-figs., Buxton Parasitol. 
Cambridge 13. 
Demodicidae. 
Systematic position, p. 310, Oude- 
mans Ent. Ber. 5. 
Demodex melesinus sp. n. Leicester- 
shire p. 38, Hirst Ann. Mag. Nat. Hist, 
ser. 9 7 ; D. chiropleralis p. 367, gliri- 
colens p. 368, talpae p. 370 spp. n. 
England, soricinus p. 368, bovis p. 371, 
melecinus, canis var. erinacei p. 372 
text-figs., Hirst Proc. Zool. Soc. Lon- 
don 1921. 
Tyroglyphidae. 
Key to genera, Newstead & Morris 
79. 
Aleurobius farinae p. 6 pi. i text- 
fig., Newstead & Duvall 77; pp. 11 
20 pi. vi, Newstead & Morris 78. 
