574 Bashford Dean Memorial Volume 



on a yolk measuring 100 x 70 mm. This is portrayed in color in Figure 49, plate V. 

 All these measurements are of the original drawings. 



When one considers these measurements of such huge eggs as had never before been 

 recorded of any animal marine or terrestrial (save only the ostrich), it is no wonder that 

 Dean wrote (1903, p. 487) that "'Chlamydoselachus has specialised in the line of producing 

 large eggs, the largest indeed among recent animals, ostrich hardly excepted". But we 

 will consider some eggs that exceed even the very large ones of Chlamydoselachus. 



SIZES OF EGGS AND EMBRYOS OF ISURID SHARKS 



Interestingly enough at about the very time that Dean was collecting adult speci' 

 mens of Chlamydoselachus and studying their eggs in the Sagami Sea, Fran? Doflein 

 was also making very extensive collections of marine fauna from the same waters. He 

 either collected or at any rate saw specimens of the frilled shark, for in his book (1906, p. 

 257) he figures a male specimen — the best portrayal (Text-figure 5 herein) yet published 

 of the male fish. He also obtained a huge shark egg and later described it in the follow 

 ing terms: 



The eggs of a giant shark were to me one of my most surprising discoveries. I had often 

 gotten these eggs from the fishermen but I never obtained the mother fish. They were, 

 however, taken from the mother fish, which evidently belongs to the viviparous sharks. 

 With their enormous yolks, they seem to be the largest eggs yet known from the animals of 

 that region. They were considerably larger than ostrich eggs [150 mm. long]. One could 

 tell them from the eggs of other sharks by the fact that the embryo was not connected with 

 the yolk sac by a long, ribbon-like umbilical cord, but grew directly from it. 



When I had read thus far, I strongly conjectured that these were eggs of Chlamydo' 

 selachus, particularly since they came from a viviparous shark and since Doflein knew and 

 figured Chlamydoselachus in his book. But fortunately, on the page following the para- 

 graph quoted, Doflein figured one of these eggs and embryos. It is plainly a young Isurid 

 shark, and the statement is added that the yolk sac has a (long?) diameter of 220 mm. No 

 size is recorded for the little shark, but it is still comparatively young, probably not more 

 than one-quarter grown. 



Doflein brought back to Germany two of these huge Isurid uterine eggs along with 

 his other Japanese fish collections. These eggs and embryos were turned over to Johannes 

 Lohberger who made a thorough study of their external morphology and internal anatomy 

 (1910). He found that the larger and older embryo (Text-figure 20 herein), after being in 

 preservative for four years, was 553 mm. long (21.8 in.) and 63 mm. wide where it rested 

 on the yolk mass. The length of the yolk mass was 211 mm. (8.3 in.) and its transverse 

 diameter 123 mm. (4.85 in.). The weight of embryo and yolk was 2.68 kg. =5.9 lbs. 

 The size of the female Lamna from which embryo and eggs were taken is not given and 

 probably was not obtained. 



In the same year that Lohberger published on his Lamnid embryos from Japan, 

 Shann (1910) described embryos of Lamna cornuhica from Scottish waters. He 

 quotes H. C. Williamson that the largest porbeagle embryo he had ever seen was "19 

 inches in total length ... the yolk measuring 9.25 inches in length". Shann's description 



