( 543 ) 



In the female the seventh steruite, fig. 15, has a different outline from that of 

 the other three species, and bears more hairs arranged in different positionB. The 

 eighth tergite, fig. 12, is more densely covered with hairs than in the other three 

 species. The hairs are arranged in two areas, the portion of the tergite between them 

 being hairless. On the ventral area of the tergite some of the hairs are thicker, but 

 they are not so spine-like as in the other species. 



The abdominal gland (fig. 20), is slender, the proximal portion being three times 

 as long as it is wide. 



I have found this species parasitic only on the House Martin, Ghelidon urbica. 



4. Ceratophyllus styx* sp. nov. figs. 5. 7. 8. (? 16. ?. 



A much more hairy species than the others, and generally about the same size 

 as C. hirundinis. Both sexes have the middle hair of the three dorsal apical hairs 

 of the seventh tergite not twice the length of the other, as is the case in the three 

 other species. (Cf. ante, p. 540). 



In the male the eighth tergite, fig. 7, bears many hairs externally, these being 

 especially dense on the apical margin. The area covered with bristles on the internal 

 side is rather more extended than in gaUinae, and is further bordered by a double 

 series of spines (fig. 8). 



The eighth sternite (fig. 5. VIII. v.) curves gradually ventrally towards the end, 

 bearing numerous hairs. It terminates proximally in a double membraneous lobe 

 similar to that in hii'undinis. 



Process p of the ninth tergite is not club-shaped, it is shorter than this part in 

 columbae and hirundinis, but is longer than in gallinae, and is oblique at the end. 



The movable finger (fig. 5. f.) is somewhat similar in outline to that of columbae, 

 but the hairs are arranged differently. There are four hairs in the centre of the 

 anterior margin of about equal length, and three at the tip, of which the middle one 

 is the longest. 



The ninth sternite (fig. 5. IX. v.) has the distal portion longer and more slender 

 than in the other species. 



In ihe female the distal segments of the abdomen are much more hairy than in 

 the other species, as are also the sternites of the other abdominal segment. 



The seventh sternite (fig. 16) bears numerous hairs. The mesial sinus is 

 triangular in shape, the lobes being sharply angulated. 



The present species is parasitic on the Sand Martin (Cotile riparia). 



• Ceratnphyllvs bifasciatrts Curtis, Brit. EnUmol. IX. (1832) No. 417, from the S.and Martin, is 

 a " nomen nudum," and must consequently be rejected. 



