Enduparasites from Chickena. 243 



(1909, p. 590). My specimens are all from the sulnirlis of 

 Melbourne. 



Davainta tetragona (Molin, 1858). Blanchard, 1891. 

 This cestode also has only been previously recorded for Aus- 

 tralia by Mr. Johnston (loc. cit.) from New South Wales. My 

 specimens were sent by Dr. Dodd from Rockhampton, Queens- 

 land. I have not, so far, been able to obtain any specimens from 

 Victorian chickens. 



Davainra rariaiis (sp.n.) (Pis. XXXI.-XXXITl.. Figs. 1-13). 



This new species I have so far only found amongst those 

 handed to me by Professor Gilruth, from one of the outer eastern 

 suburbs of Melljourne. At first glance it will almost certainly 

 be identified with Davaiiiea ijroylottina, and it is only on close 

 examination of the head with its rostellum and suckers — the 

 characters of which are oft-en extremely diificult to see — and 

 also of sections of the body, that one is convinced that this 

 cannot be that species. In difterent respects it suggests a com- 

 bination of some features of D. proyJottina with others of D. 

 echinohuthrtJa. 



The specific name has been given in reference to the great 

 variability in the conformation of the strobila, some of the 

 variations in which are given herewitli (Figs. "3 to 7). as drawn 

 with the camera lucida. 



Description. — Strobila .7 to 1.8 mm. long by .33 to .68 mm. 

 bioad. Head club-shaped to globular or spherical, .07 mm. to 

 .155 or even .217 mm. long by .1 to .19 mm. broad. Tfie neck, 

 which is often hardly present at alj, may be up to .092 mm. 

 long, and from .059 to .11 mm. wide (only rarely the former). 

 The retractile rostellum is broad and much depressed ; its 

 antero-posterior diameter varies from .009 and .016 (completely 

 everted) to .026 mm., and its lateral diameter .044 (and once 

 .033) mm. to .075 mm. Tlie middle region of the fully everted 

 rostellum carries a row of hooks .0075 to .009 mm. long. These 

 hooks, 44 to 50 in number, though not varying much in length, 

 are arranged in an alternating manner (as shown in Fig. 1). The 

 shaft or prong is bar-like, nearly straight, in the middle two- 

 thirds, but when seen in face view cuneate or broadly wedge- 



17a 



