The Embryology of Chlamydoselachus 577 



I mistakenly did not record the measurements of the yolks. Since the capsules are not 

 round but flattened dorsoventrally, it would have been difficult to get measurements in 

 this dimension. 



In my notes I have measurements of 5 wind eggs recorded as "infertile". These are 

 105 mm. long x 120 in circumference; 105 x 145, 116 x 110, 122 x 145; and 130 x 146 mm. 

 I noted the measurements of 6 average'sized fertile eggs as follows: 133 mm. long x 185 

 in circumference; 134 x 192; 141 x 185 (2 capsules); 142 x 193; 150 x 190 — average 140 

 long X 187 in girth. From this it is seen that there is considerable variation in size — less 

 in girth than in length. The girth of the capsule is pretty constant because the size of the 

 contained yolk mass is fairly uniform. The variation in length is mainly due to variations 

 in form and shape in the posterior or last-formed end of the capsule. This is sometimes 

 pointed and sometimes blunt but always seemingly "pinched together". The anterior or 

 first-formed end looks "finished", the posterior end, the last to emerge from the shell 

 gland, looks unfinished. For these points see Text-figure 16. This matter of the posterior 

 or unfinished end of the capsule will be referred to later. 



It was difficult to get the weight of the yolk. This is surrounded by a clear glairy 

 fluid which slowly flows like thick syrup. Next to the shell this becomes a thick jelly 

 which adheres to the shell. At the ends of the shell this jelly forms the "plugs" already 

 noted — see Text-figure 16. These substances — glairy fluid and jelly — probably corre- 

 spond to the "white" of Nishikawa. To get at the weight of the yolk, shell and contents 

 were weighed. Then a window was cut in the upper part of the shell, and the yolk and 

 some of the surrounding glairy matter were poured out. The shell, the jelly and the re- 

 maining glairy material were then weighed. The data for my two largest eggs are as 

 follows. Egg 1, 180 mm. long x 220 mm. in girth, weighed 318 g. The shell and jelly 

 weighed 64 g. and the yolk 254 g. Egg. no. 2 was about the same size (no figures recorded) 

 and weighed 311 g. The shell and jelly weighed 56 g. and the yolk 255 g. 



From the data set out above, and from the eggs and capsules shown in Text-figures 

 16 and 21 it is manifest that, while the encapsuled egg of Ginglymostoma is very large, it 

 is not so large as that of Lamna or Carcharodon. The average for the 6 normal-sized eggs of 

 Ginglymostoma is 140 mm. (5.5 in.) long x 187 (7-4 in.) in girth. These eggs are somewhat 

 flattened and have thick heavy raphes on each side. These help increase the girth measure- 

 ments. Text-figure 16 was made from a large and entirely normal encapsuled egg. Its life 

 size was unfortunately not noted, but as shown in the text-figure, it has been reproduced 

 140 mm. in length — the average as worked out above. This is just sHghtly more than the 

 natural size of the encapsuled egg of Ginglymostoma figured by Garman (1913, Fig. 3, pi. 

 59). From these data it is seen that in size of their eggs these sharks rank thus; Chlamy- 

 doselachus has the smallest, Ginglymostoma the intermediate-sized, and the Isurids the 

 largest eggs. 



Again must comparison be drawn between the body size of Chlamydoselachus and 

 that of these other sharks. The frilled shark has an elongate slender body averaging c. 



