202 
Mr. J. 0. Westwood on the 
ascertain the structure. The six legs are formed like those of 
the common flea, the tarsi five-jointed and long, with long and 
simple ungues. The proboscis is very long, acute and horny, 
apparently composed of a single inarticulated piece ; but on exa- 
mining this, it divided into three pieces of horny texture, one 
very slender and rather curved at the tip, representing the tongue, 
and the two others identical in structure, flat, broader, less acute 
at the tip, with the sides obliquely channelled or guttered ; these 
are the mandibles. Of the maxillae, I could not discover any 
trace, although the maxillary palpi are very distinct and four- 
jointed, the second joint being the longest. Of the labium and 
labial palpi, which in Pulex are very conspicuous, I also ob- 
tained no other trace than a small and slender piece of membrane 
observed behind the tongue, and which I am by no means sure 
formed part of the mouth.® Thus it is evident that the elongation 
of the horny mandibles and tongue is obtained at the expense of 
the labium, labial palpi, and maxillae. The basal joint of the legs 
is very large and plate-like as in Pulex, and the abdomen, when 
distended, exhibits no trace of articulation, being entirely mem- 
branous. 
The insect figured by Kirby and Spence, as well as Dumeril’s 
figure 4, may be supposed to be males, or perhaps rather females, 
not being in a state of gestation. 
From analogy with such parasites as Bopyrus Squillarum, Nico- 
tlioe Astcici , & c., we may conjecture that the male when disco- 
vered will be of very minute size compared with its partner. 
From these circumstances I think we are justified in adopting 
Mr. Guilding’s views, in regarding the jigger as the type of a 
distinct genus, which may be thus characterized. 
SARCOPSYLLA.j- 
Abdomen feminae gravidse maximum, globosum, membranaceum, 
ovis repletion, segmentis destitutum. 
Rostrum (rostrulum, K.) valde elongation, corneum ; mandibulis 
elongatis, compressis, lateribus serrulatis ; lingua elongata, 
cornea, tenuissima ; maxillis inconspicuis, palpis maxilla- 
ribus elongatis, 4-articulatis, frontalibus ; labio, palpisque 
labialibus obsoletis ? 
Ilabitatio feminae gravidae (et, ut videtur, larvarum et puparum) 
intra pedes hominum, &c. 
* Both Messrs. Duges and Guerin have also detected this organ as forming 
part of the mouth, so that it must evidently represent the labium. 
t The geneiic name SarcopJiaga being already employed in the Diptera, that 
of Sarcnpsyllit may be suggested in its stead. 
