On an Ascarid from the Sperm-wJiale. 217 



All these papilla3 are suhventral in position. A row of more 

 laterally-placed papilKx3 begins on either side at about halfway 

 between the two most anterior subventral papilla?. This row 

 runs at first diagonally towards the sides of the body, and 

 then is continued anteriorly as an extremely scattered pre- 

 anal series, with a tendency to resolve itself into two rows. 

 This series extends forward for a distance of some 5 mm. 

 from the cloacal aperture. 



The tail of the female measures about 0'7 mm. in length 

 and is bluntly conical, with a small terminal button, some- 

 times sunk in a depression. The vulva is situated at about 

 19 mm. from the anterior end in a specimen 88 mm. long. 

 It thus divides the body roughly in the proportion of 2 : 7. 

 The vagina, together with the unpaired portion of the uterus 

 (fig. 3, V,), forms a continuous tube increasing rapidly in 

 diameter as it passes backwards. After forming two or 

 three sinuous bends it gives origin, at a distance of about 

 5 mm. behind the vulva, to two stout uterine branches 

 (fig. 3, u.), which are remarkably short (8 mm.). These 

 diminish suddenly in width behind, and pass into the ovarian 

 tubes, which pursue a tortuous course covering a further 

 distance of about 13 mm., and then bend forward. They 

 continue in a forward direction to a point slightly in front 

 of the posterior end of the uterine branches, thence running 

 posteriorly again, still with numerous loops disposed more or 

 less transversely to the axis of the body, and terminating at 

 about 20 mm. from the posterior end. The eggs are spherical, 

 and have thick shells with a diameter of 0*06 mm. Their 

 contents are unsegmented when ready for laying. 



It may be useful to add a table (p. 216) comparing certain 

 characters of this species with those of other members of the 

 genus occurring in Cetacea. 



The data used in this table have been taken mainly from 

 Stiles and Hassall's valuable account of the Ascaridae of 

 marine mammals in ' Report of Fur-seal Investigations,' 

 part iii. (Washington, 1899). The measurements of A. in- 

 signis have been calculated from those given by Diesing, 

 wliich are in inches and lines. It will be noted that A. phy- 

 seteris differs markedly from all the other species of which 

 sufficient data are available, notably in the extreme shortness 

 of the spicules, the form of the ventriculus, the size of the 

 eggs, the stout build of the body and the fineness of the 

 cuiicular striations. 



