548 THE ANIMAL PARASITES OF MAX 



prothoracic comb and no black spines on the head. The genus 

 Ceratophyllus of Centis has a pronotal comb and three ante-pygidial 

 chretre on each side. Two other specimens recorded : C. londiniensis, 

 Kothsch., and C. anisns, Rothsch. The former on rats and mice in 

 London, the latter on Fclis sp. from Japan and Mus norregicus in 

 California. 



Genus. Ctenopsylla, Kolen. 



This genus contains a very abundant rat and mouse species, 

 C. miisculi, Duges, which is widely distributed over the globe. 



Genus. Hystrichopsylla, Tasch. 



Large hairy fle^s, with no eyes and one or more combs on the 

 abdomen. In the Mediterranean area one species, H. tripectinata, 

 Tirah, is common on rats and mice, and also in the Azores. Several 

 others occur on rats and mice. For information concerning these the 

 reader is referred to Rothschild's papers. 



Pulex pallipes is another species found on the rat and man. 

 Systematic, Anatomical, and Biological Remarks on Mosquitoes. 



Mosquitoes come in the Nematocera, one of the sub-orders of the Diptera, 

 and are divided into numerous families, of which, however, the C-ulicida are of most 

 interest to us here. Other families as the Psychodidce and Chironomidce are also 

 of considerable importance, vide following pages. The head is small, the facetted 

 eyes are placed laterally, but there are no accessory eyes (ocelli). In front of the 

 eyes are situated the comparatively long antennae, the differences of which strongly 

 mark the distinction of sex. 1 



The antennae are composed of fifteen or sixteen segments. In the male they 

 are covered with long whorl-like hairs, while in the female the antennal hairs are 

 short differences that are perceptible even with the naked eye. 2 The proboscis, 

 which is longer than the antennae, protrudes from the inferior aspect of the head and 

 is composed of the following parts (figs. 387 and 388) : Two grooved half tubes, 

 facing one another, of which the upper one is the upper lip (labrum) and the lower 

 one the lower lip (labium), which represents a pair of coalesced maxillae. Within 

 the tube formed by the labrum and labium are the mandibles and maxillae, trans- 

 formed into instruments for piercing, and a single puncturing organ, the hypo- 

 pharynx. On the right and left, next to the proboscis, are placed the straight five.- 

 jointed palpi, the final joint of which is thickened in the male. 3 In biting, the 

 labrum. which is swollen at its free end, is not introduced into the wound like the 



1 [This is by no means always the case ; in the genera Deinocerites, Wyeomyia, Limatus, 

 Theobald, and in Sabethes, Robineau Desvoidy, they are nearly the same in both sexes. 

 F. V. T.I 



2 [This is not always the case, vide previous note. F. V. T.I 



3 [This is only so in Anophelina and in the genus Theobaldinella, Neveu-Lemaire, 

 Grabhamia, Theobald, Acartomyia, Theobald, etc. In true Culex and many other genera 

 the male palpi are pointed. F. V. T.] 



