PULEX. 



[ 544 ] 



PULEX. 



ment (fig. 9, behind /,/) ; these represent 

 rudimentary wings. 



The legs are large, especially the hinder 

 ones, and adapted for leaping. The first 

 joint or coxa {g) is very thick ; the second 

 or trochanter (h) is very small; next come 

 the femm* (i), the tibia {k), 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 membranous 

 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 bristles, implanted 

 in the centre of as many disk-like areolae, 

 each of which is ornamented with a ring of 

 rectangular or somewhat cuneate rays. The 

 portions of the pygidium between the areolae, 

 are studded with minute spines. The end 

 of the abdomen in the female (PI. 28. fig. 9) 

 is more rounded or ovate than that of the 

 male (fig. 13), which is somewhat turned 

 upwards. 



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 Mal- 

 pighian 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, without 

 eyes, and supporting two very minute an- 

 tennae; 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. 



P. irritans, human flea. Pitch-brown; 



head shining, smooth, pectinate fringe 

 absent ; 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 : anterior, 

 2, 5, 1, 3, 4 ; posterior, 1, 5, 2, 3, 4 (Bouche). 

 We have never been able to find a flea with 

 the above relative length of the joints of the 

 anterior tarsi. 



P. felis, cat's flea (P. cams, Bouche ; P. 

 irritans, Duges) (PI. 28. 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 ; poste- 

 rior, 1, 5, 2, 3, 4. 



P. canis, flea of dog and fox (PL 28. fig. 10, 

 head) {P. felis, Bouche). Pale pitch-brown; 

 head shining, smooth, punctate behind ; 

 lower part of head and protothorax with a 

 pectinate fringe; posterior tibiae much ex- 

 panded at the end; fifth joint of anterior 

 and first of posterior tarsi longest. Tarsi : 

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

 3,4. 



P. gallince, {owVs flea. Pitch -brown, with 

 shining, smooth, elongated head; proto- 

 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 proto- 

 thorax with pectinate fringe ; tarsi as in P. 

 canis. 



P. sciurorum, flea of the squirrel. Head 

 naked ; pectinate fringe on protothorax, 

 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. Tarsi : 

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



P. talpa, Curtis, flea of mole (PI. 28. 

 fig. 24). 



P. columbce, pigeon's flea. Protothorax 

 with pectinate fringe, none upon the abdo- 

 men ; antennae of male erect, those of the 

 female lying in the depression. 



P. penetrans, the chigoe or jigger. The 

 females burrow in the skin of the feet, and 

 the ova, undergoing development, enlarge the 

 abdomen to the size of a pea, causing severe 

 inflammation, &c. Rostrum very long. 

 Tropical. 



P. vespertilionis, flea of the bat (PI. 28. 

 fig. 11, head). 



BiBL. Westwood, Introduction, ^c, ii. 



