STUDIES IN NEOTROPICAL MALLOPHAGA—CARRIKER 175 
0.12), while the combined paramers are also longer and much narrower 
(0.826 by 0.0162 against 0.38 by 0.0108). 
A series of 27 males and 10 females was taken from three individuals 
of the type host at Tierra Nueva and Monte Elias, Sierra Perijé, Co- 
lombia, and one male and two females on the same host from La Cumbre 
de Valencia, Venezuela.. They are very uniform in size, markings, 
and chaetotaxy, with the exception of the number of spines along the 
posterior margins of the pleurite, which varies considerably in the 
two pleurites of the same segment (a case similiar to the number of 
teeth in the abdominal combs of hopaloceras), there often being one 
less on the right side of the abdoinen. It is a curious coincidence that 
the lesser number of spines should almost invariably be on the right 
side. It is not a case of a spine having been broken off, since when 
that happens the place of attachment is always clearly visible. This 
phenomenon is also present in the series of 7’. s. spznosus. 
MEASUREMENTS OF TRICHODOPEOSTUS SPINOSUS 
| Spinosus praegracilis 
Structure Male Female Male Female 
Length | Width Length | Width | Length! Width | Length} Width 
TEXoy Wi¢ Maga SA fe CED Yas aa A Veige Paoe Seas 196 pick os AG TALGy || Sete ees ee 2. 05 
PLOTS 2 eee ANU NLR ASU ate Aa a Qub4 yee es ONS5 | aa eeeee Ques eres eile 0. 54 
Headsitem plese os eee eee ae 0.59 | 0.825 0. 63 0.80 | 0.55 | 0.77 0. 61 0. 92 
OCCIPUT ees Set ge ON5O Pg eee ae OSb0 (4 |sa5. 2428 OS ATA Neh. ts 0. 50 
IPTOLH OLAX te ee sso seek eae ene 0.20 | 0.42 0. 206 0.48 | 0.185 | 0.41 0. 195 0. 41 
INTESOTR OT Ee eee eee ee ee Me ea 0.25 | 0.68 0. 26 0.69 | 0.24 | 0.66 0. 25 0. 66 
Mietathorax sis. 22 32 ek ek Se 0.25 | 0.586 0. 25 0.61) 0.22 | 0.56 0. 24 0. 57 
Abdomen sect dil ee ale aa 0.98 | 0.80 1.13 0.82 |} 1.00 | 0.78 1.33 0. 79 
FAM CENA eee a ONS eae 0.26 | 0.095 0. 25 0.05 | 0.29 | 0.087 0. 27 0. 05 
Basaliplatepip site ecu ae OBB ey) OLTZ) poles rece eter ees Y O44 Ove Bos eee 
RATAN ers ee ULSI OURAN O%326) MONO1LG2) | Beene eae 0.38 | 0.0108 |_---_--. 
HETEROPEOSTUS, new genus 
Genotype.—Rhyncothura carrikeri Clay. 
Diagnosis.—Superficially resembling some species of Khyncothura 
but differing from that genus in the structure and markings of the 
abdominal sclerites and especially in the male genitalia, which seem 
to be of a completely unique type and of generic significance in this 
family. 
Size medium; sexual dimorphism in shape of antennae, head, ab- 
domen, and seventh abdominal segment. First antennal segment in 
male lengthened and swollen; second segment enlarged to a lesser 
degree; third with distal end elongated, and the minute fourth at- 
