W. S. Patton and C. Strickland 
341 
Melophagus ovinus, life-cycle shortly to be described by Swingle, part 
has been described by Flu (1908). 
11. Crithidia Christopher si Novy, parasitic in the alimentary tract 
of Rhipicephalus sanguineus. 
12. Crithidia haemaphysalidis n. sp. Patton, parasitic in the ali¬ 
mentary tract of Haemaphysalis flava. 
13. Crithidia robertsoni n. sp. Patton, parasitic in the crop 
diverticula and intestine of Pontohdella muricata, part of life-cycle 
described in detail by Robertson (1907), method of infection not clear; 
it is believed by Brumpt and Robertson to be connected with T. rajae, 
this is however not proved. 
14. Crithidia ctenopthalmi n. sp. Patton and Strickland, parasitic in 
the alimentary tract of Ctenopthalmus agyrtes, part of the life-cycle 
described. Other unnamed species have been found in Loemopsylla 
cleopatrae and Ctenocephalus felis. 
15. Crithidia haematopini n. sp. Patton, parasitic in the alimentary 
tract of Haematopinus spinulosus, part of the life-cycle has been 
described by Prowazek. 
It is impossible to include in this list doubtful species such as 
T. drosophilae ; the flagellate found in the ovaries of Chrysops dimidiatus 
by Ziemann (1905) which may be but a stage of a parasitic flagellate 
and another found by Leger in Nepa and named Otomonas tremula. 
It is also impossible to include many more which have been found 
in bugs by Donovan in Madras, by Leger, Brumpt, Leydig and others in 
leeches, and by Leydig in ticks; it is possible that some of the 
flagellates described by Leger as Herpetomonas may eventually have to 
be placed in the genus Crithidia. 
In conclusion we wish to thank Professor Nuttall for his kindness in 
helping us to complete this work, and we hope that the critical remarks 
made in this paper may be of some use in guiding subsequent workers 
to a better understanding of these parasitic flagellates of arthropods and 
leeches. 
Appendix by Captain Patton. 
A recent paper by Mesnil and Brimont entitled “ Sur un 
Hematozoaire nouveau ( Endotrypanum , n. gen.) dun Edente de Guyane” 
( Compt. Rend. Soc. Biolog. T. lxv. No 35, 11th Dec. 1908, pp. 581-583, 
7 figs.) calls for some remarks. The parasite here recorded was 
apparently found by Brimont in the red blood corpuscles of the common 
