304 CLASS VIII. 



represented by this ligula 1 . The maxillae are two small plates at 

 whose base are attached the feelers stretching forwards, and which 

 were formerly regarded as antennae ; they have four oblong joints, 

 of which the second and the fourth are the longest. 



The intestinal canal of the Flea is short and straight ; its stomach 

 is cylindrical, the small intestine as long as the stomach, and rectum 

 short. There are four short and wide urinary tubes, which are 

 implanted at the inferior orifice of the stomach. At both sides are 

 two salivary vessels in form of round vesicles, whose efferent ducts 

 coalesce to form a canal on each side of the oesophagus, which 

 mounts tortuously to the mouth. 



See RAMDOHR, AWiandlung ub. d. VerdauungsiverTczeuge der Insecten, 

 s. 202. Tab. xxni. fig. 2. 



Comp. on this family A. DUGES, Recherches sur les Caracteres 

 zoologiques du genre Pulex, et sur la multiplicity des especes quil 

 renferme. Ann. des Sc. nat. xxvu. 1832, pp. 165 175, PL iv., and 

 P. F. BOUCHE, Bemerkungen uber die Gattung Pulex, Nov. Act. 

 Acad. Gees. Leop. Car. Tom. xvn. 1835, p. 501 508 (this writer 

 considers the parts indicated above as mandibles to be lacinice of 

 the under-lip, and gives the maxillary palps five joints). 



Sp. Pulex irritant L. (in part), HOOKE Micrographia Tab. 34 (a large 

 figure of full 15 Rhenish inches, or 4 decimeters in length), DUGES 1. L 

 fig. i (both figures represent the female). Ordinarily this species is con- 

 founded with others which occur on the dog and domestic cat, Pulex canis 

 DUGES, Pulex canis and Pulex felis BOUCHE. To the last-named refer the 

 figures of ROESEL, Ins. II. Muscar. atque Culicum, Tab. 11 iv. (Tab. in. 

 fig. 10, representing a male, refers according to BOUCHE to Pulex irritans). 

 Moreover these species can bear leaving their natural habitat for a time, 

 and thus Pulex irritans may pass on to dogs, Pulex canis on to man. A 

 particular species also occurs on fowls, Pul. gattince, SCHRANK, BOUCHE". 

 All the species of this genus are small insects ; the largest hitherto known, 

 Pulex gigas, has only a length of two lines, Fauna Bor. Americana of 

 J. RICHARDSON, Vol. iv. 1837. The hip (coxa] of the feet is as large as J 

 the thigh (femur) and very thick ; the fore-feet are placed far forwards, 

 almost under the head. The abdomen is large, on the upper surface in the 

 male, concave ; in copulation the female is placed on the back of the little 

 male. The eggs are white, oblong, sticky. In the summer season the 

 larvae come forth after a lapse of six days, having no feet, and resembling 

 small, white worms. LEEUWENHOECK brought them up on dead flies, 

 ROESEL on dead gnats and dried pigeon's blood. Blood that has followed 



1 DUGES, Ann. des Sc. nat. sec. Serie. Tom. vi. 1836. Zool. p. 130. 



