PULEX. 



[ 647 ] 



PULEX. 



ones, and adapted for leaping. The first 

 joint or coxa (Y/) is very thick; the second 

 or trochanter (k) is very smaU ; next come 

 the femur (2), the tibia (7c), and lastly the 

 five-jointed tarsus (/), which is terminated 

 by two curved and denticulate claws, with 

 a lobe or heel at the base. 



The abdomen of the female has nine 

 distinct rings, the first seven of which are 

 each furnished with a pair of stigmata (a), 

 and consist of horny arches with mem- 

 branous margins. The eighth arch, which 

 has no membranous margin, is strengthened 

 by a horny band furnished with fine hairs, 

 to protect the orifice of the last stigma. 

 The ninth and last segment, called the 

 pygidium (fig. 9x and PI. 1. fig. 13), is 

 somewhat kidney - shaped or two - lobed, 

 folded on the dorsum, and exhibits twenty- 

 five to twenty-eight stiff and longish bris- 

 tles, implanted in the centre of as many 

 disk-like areolee, each of which is orna- 

 mented with a ring of rectangular or some- 

 what cuneate rays. The portions of the 

 pvgidium between the areolae are studded 

 with minute spines. The end of the abdo- 

 men in the female (PL 35. fig. 9) is more 

 rounded or ovate than that of the male 

 (fig. 13), which is somewhat turned up- 

 wards. 



In some species the segments of the 

 thorax and abdomen are furnished with a 

 posterior pectinate fringe. 



The alimentary canal is short and straight; 

 the stomach cylindrical ; the small intestine 

 as long as the "stomach, and the large intes- 

 tine short. Four short and broad Malpighian 

 vessels open into the lower orifice of the 

 stomach; and the ducts of two round salivary 

 vesicles unite to a single canal ascending in 

 a coiled form on each side of the oesophagus 

 towards the mouth. 



The eggs of the flea are white, elongated, 

 and viscid outside. The larvae have no 

 legs ; they are elongated, resembling minute 

 worms, and very active, coiling themselves 

 into a circle or spiral, and serpentine in 

 their movements. The head is scaly, with- 

 out eyes, and supporting two very minute 

 antennae ; the body has thirteen segments, 

 with small tufts of hairs, and at the end of 

 the last are two little hooks. 



The species are numerous (twenty-five, 

 Gervais) ; but their characters are not well 

 defined. One species (P. terrestris) is said 

 to exist under brush-wood; and one (P. 

 Boleti) in Boleti. 



P. irritans, human flea. Pitch-brown ; 



head shining, smooth, pectinate fringe ab- 

 sent ; legs pale ; femora of posterior legs 

 with hairs inside ; second joint of the tarsi 

 of the anterior pair of legs and first joint 

 of posterior tarsi longest. Tarsal joints, in 

 respective order of greatest length: an- 

 terior, 2, 5, 1, 3, 4 ; posterior, 1, 5, 2, 3, 4 

 (Bouche). We have not been able to find 

 a flea with the above relative length of the 

 joints of the anterior tarsi. 



P. fells, cat's flea (P. canis, Bouche; PI. 

 35. fig. 9). Pale pitch-brown ; head naked, 

 shining, smooth, with delicate scattered 

 dots; coxae and femora almost naked; 

 fifth joint of anterior tarsi and first joint 

 of posterior tarsi longest. Tarsal joints: 

 anterior, 5, 2, 1, 3, 4; posterior, 1, 2, 5, 

 3,4. 



P. canis or serraticeps, flea of dog and fox 

 (P.fefo, Bouche ; PI. 35. fig. 10, head). Pale 

 pitch-brown ; head shining, smooth, punc- 

 tate behind ; lower part of head and pro- 

 thorax with a pectinate fringe; posterior 

 tibiae much expanded at the end ; fifth 

 joint of anterior and first of posterior tarsi 

 longest. Tarsi : anterior, 5, 2, 1, 3, 4 ; pos- 

 terior, 1, 5, 2, 3, 4. 



P. gallinte, fowl's flea. Pitch-brown, 

 with shining, smooth, elongated head ; pro- 

 thorax with a pectinate fringe; first joint 

 of all the tarsi longest. Tarsi: anterior and 

 posterior, 1, 2, 5, 3, 4. 



P. martis, flea of the marten and dog. 

 Postero-inferior margin of head and pro- 

 thorax with pectinate fringe ; tarsi as in P. 

 canis. 



P. sciuri, flea of the squirrel. Head 

 naked ; pectinate fringe on prothorax, none 

 upon the abdomen. Tarsi: anterior, 1, 5, 

 2, 3, 4 ; posterior, 1, 2, 5, 3, 4. 



P. erinacei, flea of hedgehog. Head 

 naked, mesothorax with a fringe. Tar-d : 

 anterior, 5, 2, 1, 3, 4 ; posterior, 1 , 2, 5, 3, 4. 



P. talpa, Curtis, flea of mole (PI. 35. 

 fig. 24). 



P. columba, pigeon's flea. Prothorax 

 with pectinate fringe, none upon the abdo- 

 men ; antennas of male erect, those of the 

 female lying in the depression. 



P.penetrans (Rhynchopriori), the chigoe or 

 jigger. The females burrow in the skin of 

 the feet ; and the ova, undergoing develop- 

 ment, enlarge the parent-abdomen to the 

 size of a pea, causing severe inflammation, 

 &c. Rostrum very long. Tropical. 



P. vespertilionis, flea of the bat (PI. 35. 

 fig. 11, head); the first seven segments of 

 the abdomen with pectinate fringes. 



