4 572 Bashford Dean lAemorial Volume 



Its width is 23 mm. and its length over the processes (but excluding the tendrils) is 102 

 mm. At the larger end is a conical process. The long pointed end of the capsule breaks 

 up into a group of tendrils measuring about 10 mm. The surface of the capsule exhibits 

 very fine striations. Very clear is the longitudinal ridge or raphe extending from the 

 tendrils along the small end of the egg capsule to and across the base of the conical process. 

 Not visible is the corresponding one on the other side. At the lower side of the larger 

 end ot the capsule is a clearly delimited pale area. What it is I do not know. This egg 

 apparently contained no yolk whatever and hence it is called "wind egg". The color as 

 shown in the figure is presumably that common to all egg capsules. 



ROUND EGGS OF THE FRILLED SHARK 



Last among Dean's materials for the study of encapsuled eggs are three drawings of 

 round eggs reproduced as Figures 4, 5, and 6 of plate I. These are labelled C, B, and A 

 on the drawings, and are listed in this order in Dean's notebook in his writing, as indi' 

 eating their progressive stages of development. Each egg capsule is round and has short 

 curved processes. These eggs will be considered here in the order of size. 



Egg A (Figure 6, plate I) in the original drawing measures 129 mm. over the processes, 

 and the diameters of its yolk mass are c. 88 mm. in the line of the processes x 87 wide. 

 Of the three eggs, its processes are the longest and slenderest, are of about the same size 

 and length, and are curved in the same direction. Egg B (Figure 5) is 115 mm. over the 

 processes, and its diameters are c. 87 x 96. Its processes are short and stumpy, are of 

 about equal size, but are twisted in opposite directions. Egg C (Figure 4) is 116 mm. over 

 the processes, and its diameters are c. 90 x 89. Its stumpy processes are short, of unequal 

 size — one more than double the size of the other — but are curved in the same direction. 

 All these processes appear to be "stumpy"', but it may be that they were sharply curved 

 away from the artist's line of sight and were longer than they appear in the drawings. 

 Those of Egg A (Figure 6) certainly recall the longer process portrayed by Nishikawa in 

 my Text-figure 4, and by Dean in his Figures 7 and 9, plate I. In this respect this capsule 

 approaches what has been taken as the normal type. 



In the capsule of each egg the raphe extends across the germinal region, where it is 

 drawn much wider. It runs out onto and helps form each process. The striae are not 

 visible over the egg but show faintly at the poles, where they converge and extend out 

 on the processes. The formation of these processes is not easy to understand and so far 

 as I know has never been explained. The anterior process of the capsule must be formed 

 in the lower outlet of the shell gland while the egg in the shell gland is having its capsule 

 laid down. As I shall show later the posterior process is formed as and when the en- 

 capsuled egg passes out of the gland on its way to the uterus. The exit orifice of the shell 

 gland is small and its sphincter muscle evidently constricts the ends of the shell while 

 they are still soft and gelatinous. While the processes are being formed, the striae on 

 them are laid down in a way not as yet understood. 



