376 
Ascarids in the British Museum 
the two posterior horns occurring at 10 mm. from the vulva. The horns 
are 18 mm. long, and both these and the unpaired uterus are straight. 
The ova are spherical, and measure 0-05 mm. in diameter. 
This species has a ribbon-hke ventral excretory gland, similar to 
those of the previously-described forms, and measuring 1 mm. in width. 
The duct of the gland opens, as in the other cases, by a small pore 
between the ventro-lateral lips. 
This form having now been placed on a more satisfactory basis, as 
a valid species, it becomes necessary to propose a new name for it. 
This necessity arises owing to the fact that Rudolphi (1793, p. 13), 
published the name Ascaris bicolor for another worm; and although he 
subsequently (1809, n. p. 173) changed this name to Ascaris truncatula, 
the original name, according to the law of priority, must stand, and 
consequently the name A. bicolor for Baird’s species is preoccupied. 
It is therefore proposed to substitute the name Ascaris rosmari. 
REFERENCES. 
Baird, W. (1853). Catalogue of the Species of Entozoa in the Collection of the British 
Museum. 
-(1868). [vide Murie, J., 1868.] 
Blanchard, E. (1849). Recherches sur l’Organisation des Vers. Ann. Sci. Nat. 
(3), xi, 106. 
Diesing, K. M. (1851). Systerna Helminthum, n. 
-(1860). Revision der Nematoden. Sitzungsber. d. k. Akad. Wiss. Wien, xlh, 
(published 1861), 595. 
Jagerskeold, L. A. (1894). Beitrage zur Kenntniss der Nematoden. Zool. Jahrb. 
(Anat.), vn, 449. 
Krabbe, H. (1878). Saelernes og Tandhvalernes Spolorme. K. Dansk. Yidensk. 
Selsk. Forh. 43. 
Leiper, R. T. and E. L. Atkinson (1914). Helminthes of the British Antarctic 
Expedition, 1910-1913. Proc. Zool. Soc. 222. 
Leiper, R. T. and E. L. Atkinson (1915). Parasitic Worms. British Antarctic 
(Terra Nova) Expedition, 1910, Zoology, n, 19. 
Linstow, O. von (1878). Neue Beobachtungen an Hehninthen. Arch. f. Naturg. 
xliv, 218. 
-(1880). Hehninthologische Untersuchungen. Arch. f. Naturg. xlvt, 41. 
-(1884). Helminthologisches. Arch. f. Naturg. l, 125. 
-(1888). Report on the Entozoa. Challenger Reports, Zoology, xxm. 
-(1900). Die Nematoden, in Romer and Schaudinn, Fauna Arctica (Jena), 
i, 119. 
