Blood Parasite!<. 239 



distinct here) in the centre of the body, are seen to be arranged 

 in an irreguhir double line, especially in the head region. The 

 gaps corresponding to 1, 3 and 4 in No. 1 are present, but in 

 somewhat different positions in the length of the body. In the 

 place of the special group of nuclei marked 2 in Fig. 1, there is 

 occasionally a clear round pink spot surrounded by a deep blue 

 zone. This form of larva is generally 108 /x long by 5.6 /x wide. 



No. 3. — The third type of larva, as shown in Fig. 3, is very 

 much less differentiated than either of the others, and though 

 nuich more frequent than No. 2, is less so than No. 1. The 

 head is sometimes hyaline, sometimes not, the tail is much more 

 pointed than in either of the other types. Only one clear spot 

 is visible, presumably the tail spot (No. 3). No difference in 

 character or arrangement can be detected in any of the nuclei, 

 the whole of which stain much more deeply than those of Nos. 1 

 and 2, giving this form a distinctly darker blue colour as com- 

 pared with the other larvae. 



In length these vary from 112 /a to 126 fj long (very rarely to 

 136 fx), and ai*e 4.5 fx wide, i.e., narrower than type No. 2. The 

 tail spot is generally about 3-8th of the body length from the 

 tip of the tail. 



In none of these larvae could the sheath be definitely deter- 

 mined. 



As will be seen (Von Linstow, 1891, p. 301-2), these larvae 

 are all distinctly smaller than those observed by Von Linstow 

 in Fihiria triruspis, and by Borell in the crow, but are not 

 unlike in size those described by Ecker and Herbst in several 

 species of crow, as larvae of FiJaria attenuata. It is not 

 unlikely that the present form may prove to be one or other 

 of these species, but in the meantime the name of Microfilaria 

 gijni norliinae. is used for facility of record. 



EXPLANATION OF PLATES XXVIII.-XXX. 



All figures drawn under obj. 1/12 oil-immersion, oc. 4, with 

 camera lucicla. 



