100 ME. GAEDIXEPv ANB PEOF. EETNOLDS ON THE [Feb. I912, 



Amphioxus) — the longest being next the dorsal line of the 

 carapace. 



The dorsal margin is straight, and is 17 mm. long; its posterior 

 margin is strongly incurved or emarginated, but produced backwards 

 where it unites with the ventral border to form a strong projecting 

 spine. 



The ventral margin is 25 mm. long, and very arcuate, terminating 

 posteriorly in an acute spine. 



The caudal segments measure together about 15 mm. in length 

 and lie close to the posterior margin, being displaced and bent 

 upwards. 



Fig, 3. — Carjocaris kilbridensis, sp. nov. (Tivice the natural size.) 





d. 



a 





cs. 



a -' 



..,.^-^-<c-— --^ 



>■ 



rf 









■^ 



r 



Itr-^ 







"^ 





"^^--;. 











V: 



[ « = Autei'ior border. v — Ventral border. 



lt.= Labial tentacles or spines, j) = Posterior border, 



= Ova. e.s. = Ephippial shield.^ 



d = Dorsal border, c.s. = Three caudal segments.] 



What appears to me to be of great interest in this specimen, 

 is the presence, near the centre of the carapace, and evidently, 

 as it seems to me, enclosed within it, at its broadest part, of 

 two round bodies (each measuring about 2^ mm. in diameter) 

 which appear to be eggs, and may possibly be homologous with the 

 pair of ephippial eggs, so often observed in DajjJinia, especially 

 protected to retain their vitality by their additional covering during 

 the cold of winter — or when the water in which the parent lived 

 had been dried up by evaporation, leaving the mud containing the 

 eggs to solidify, and so remain imprisoned, until, after a more or 

 less protracted period of drought, the arrival of the rainy season 

 again sets them free — when the eggs are duly hatched out. 



I may mention that, many years ago, I received by the favour of 

 Mr. Clement Eeid, F.R.S., a number of these small ephippia, which 

 he had picked out of the ancient Freshwater Bed at Mundesley on 

 the i^orfolk coast, attesting the almost indestructible nature of these 

 minute siliceous envelopes. 



I have myself hatched out a number of these ephippial eggs sent 

 to me which had been obtained from the dried-up mud of a stream 

 in the Orange Free State, after some years' imprisonment in a 

 dry box in the British Museum (Natural History). 



The late Dr. AY. Baird, in a similar manner, brought to life quite 

 a number of Entomostraca from a sample of dried-up mud which 



