182 THE "BOTTLE-NOSE RAY " AND ITS EGG-PURSE. 



include not only the alar series but also a group at the margin opposite 

 the eyes, the dorsal surface is generally destitute of large spines. 

 Some are present on the snout and on the supra-orbital ridges. On the 

 tail is a single median series, extending some way on to the back, and a 

 lateral sub-marginal series, which, if sometimes single, may frequently 

 be complex. The ventral surface is gcneralhj smooth, except along the 

 anterior margin of the disk, tohich is occupied hj a very distinct border of 

 asperities and spines. There are no UaeJc or grey markings of any sort on 

 the ventral surface, uihich in large examples is dead ivhite, without any 

 pigment whatever. Young examples have a border of dark pigment on 

 the ventral surface of the wings ; the under side of the tail is also dark. 

 The teeth are pointed in both sexes. 



The egg-purse does not greatly differ, in so far as concerns the shape 

 of its body, from that of the common grey skate, E. hatis. Using the 

 topographical terms which are applicable while the purse remains in 

 the ovary, the body is roughly oblong, but slightly constricted 

 posteriorly. The anterior margin is truncate, the posterior margin 

 broadly concave. Its greatest length in the middle line is 17'-4 cm. 

 (6} inches), and its greatest width 13-8 cm. (oyV inches); but the actual 

 cavity is only about IS'o by 10-5 cm. (5]- by 4i inches). 



The purse is thus of a very large size, apart from the attachment 

 processes. Dorsally and veutrally the surface of the egg-cavity is 

 somewhat inflated, but the convexity is greatest dorsally, and the 

 lateral edges of the purse are rolled up in a ventral direction. 



The attachment processes are characteristic. The posterior processes, 

 about 87 cm. (3xV inches) in length, as measured from the level of the 

 anterior edge of the body, are stout, but flattened, tapering to a 

 width of -9 cm. (| in.) at the roughly truncate extremity. They are 

 strongly bent in a ventral direction, and incline somewhat towards each 

 other. The anterior processes are long and ribbon-like. Tapering from 

 a width of 2-2 cm. (J in.) at their origin to one of about -6 cm. (| in.) at 

 the extremity,-'' they measure about 24-5 cm. (9f inches) in total length. 

 They are very thin, but supported by a thickened longitudinal ridge. 

 Each process is inwardly curved so as to meet and cross its fellow 

 at about two-thirds of its length, the curve being thereafter continued 

 in a backward direction. The axis is gradually rotated so that the 

 outer edge of the distal part of each filament is ventral in position. 



In texture the purse is opaque, and, after exposure to sea water, 

 of a dark olive-brown colour, as is the case with the purses of most 

 rays. The fine longitudinal ridges are most distinctly beaded : each 



* The process terminates, in some specimens, in an indefinite gelatinous tissue, which 

 is probably produced in others as a filament. 



