PULEX. 



[ G46 ] 



PULEX. 



with an immersed, ostiolate peridiole, bear- 

 ing long cilia at the mouth ; pale, orange, 

 or blackish in colour. The Urediuous fruits 

 are scattered or grouped in circles, devoid 

 of a proper peridium, but surrounded some- 

 times by thickish cylindrical paraphyses, 

 very rarely connected below into a mem- 

 brane, forming a kind of ciliated peridium ; 

 the stylospores are round and mostly spinu- 

 lose, with three or four equidistant pores. 

 The Puccineous fruits are also scattered or 

 grouped in circles, sometimes containing 

 only their proper spores, sometimes with 

 Uredinous spores intermixed, destitute of a 

 proper peridium, but, lilie the Ureclines, 

 having sometimes a false envelope formed 

 of continent paraphyses ; their spores, form- 

 ing the chief distinctive character of the 

 genus, are biloculai; oblong or globose, 

 rounded-obtuse or acuminate at the apex, 

 smooth or spinulose, the upper locidus with 

 a pore at its summit, the lower with a pore at 

 the upper end of one side (next the septum). 

 These plants occur commonly on the 

 Grasses and many otlier herbaceous plants, 

 often changing colour during the summer, 

 being yellow or orange when the Uredinous 

 spores are ripe, and afterwards blackish 

 when the Puccineous form is matin-e. 



The species are very numerous ; but some 

 of those formerly included under this name 

 are now removed to other genera, such as 

 Uromyces, Triphragmimn, Sec. (See Ure- 

 DiNEi.) P. yraininis is common on corn 

 and other grasses (Mildetv) ; among the 

 other frequent species are P. Caricis, Poly- 

 yonorum, Mentlice, Anemones, Buxi, &c. 

 Robin describes a Pi(cci>u'a, apparently on 

 the authority of Ardsten, a Swedish phy- 

 sician, found upon the human head in Favi^s. 

 From his description it appears to be a true 

 Puechiia, and should hold its place (P. Favi, 

 Ardst.) among the species. But Avhat is 

 more remarkable, it occurs together with 

 Achoriun ScJianleimi, the latter presenting 

 itself as a constituent of the cups or crusts, 

 while the Puccinia occurs afterwards on the 

 desquamations of the epidermis. 



BiBL. Berk. Br. Fl. ii. pt. 2. 303 ; Ann. 

 N. H. vi. 439; ibid. 2. v. 4G2, xiii. 461; 

 Tulasne, Ann. Sc. Knt. 3. vii. 12; ibid. 4. ii. 

 77, l.'W & 182; Levcille, ibid. 3. viii. 309; 

 De liary, Brandpihe, 30 ; Fries, Sum. Vey, 

 513; Pvobin, Veyct. Pa rasif. 2. (Jl3; Bagnis, 

 Jn. Mic. Soc. 1878, i. 27. 



PULEX, Linn. (Flea).— A genus of In- 

 sects, of the order Siphonaptera (Suctoria 

 or Aphaniptera), and family Pulicidse. 



CImr. As there are only the single family 

 and genus in the order, the characters of 

 the latter are distinctive. 



Head small (PL 35. fig. 9), compressed, 

 rounded above, truncate in front, in some 

 species with an inferior pectinate fiinge of 

 blackish-brown teeth ; eyes one on each 

 side, round, simple, smooth ; behind each 

 eye is a cavity or depression, at the bottom 

 of which the antennse are attached ; an- 

 tennfe (figs. 9 a, 12) four-jointed, their form 

 varying in the difR-rent species, the third 

 joint very minute, and forming the cup- 

 shaped base of the terminal joint or piece, 

 which in some species is furnished with 

 numerous transverse incisions, representing 

 as many distinct joints; in some the an- 

 tennae extend out of the depres^-ion, and are 

 carried erect. 



Oral appendages (PI. 35. fig. 9 e) compos:^d 

 of several parts : 1 . (PL 33. figs. 32 d, 33 d) 

 The uppermost is single, and consists of a 

 thin, flattened seta, coars*4y toothed on the 

 upper surface, and traversed throughout its 

 entire length by a canal, upon the walls of 

 which a very slender trachea runs, and from 

 which very minute canals, terminating at 

 the end of the little teeth, are given ofl". 

 This is the suctorial organ, and perhaps 

 corresponds to the labrum, but is sometimes 

 regarded as the lingua or ligula. 2. (figs. 

 32/, 33/) Two quadrangular, narrow, and 

 elongated plates, each furnished with longi- 

 tudinal ribs, and with fine teeth ; these are 

 the lancets or scalpella, and correspond to 

 the mandibles. 3. (PL 33. fig. 32 y) Two 

 somewhat triangular or leaf-like plates, the 

 maxillae ; to which are attached — 4. ( PL 33. 

 fig. 32 h ; PL 35. fig. 9 d) Two nearly cylin- 

 drical four-jointed maxillary palpi. 5. (PI. 

 33. fig. 32 Jc ; fig. 33 Jc) Two labial palpi, in 

 the form of sheaths, four-jointed, thickened 

 at the back and membranous at the margin ; 

 these palpi arise from near the apex of — 

 6. (PL 33. fig. 33 /) A small membranous 

 labium, with the still smaller mentum (PL 

 33. fig. 33 7n) at its base. 



Thorax composed of three segments, each 

 consisting of an upper (PL 35. fig. 9, c), and 

 a lower piece //; from the lower arise the 

 corresponding legs. The two posterior seg- 

 ments of the thoi'ax aroeach furnished with 

 a pair of plates, the hindermost of which is 

 longest, and nearly covers the sides of the 

 first and part of the second abdominal seg- 

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

 rudimentary wings. 



The legs are large, especially the hinder 



