BIOLOGY. 317 



worms. "We now know, in both groups, of animals laying eggs 

 which produce embryos developing directly into the adult form ; 

 of others which present strange larval conditions, whicli either 

 become completely altered so as to form the adults, or bud off" 

 from their interiors a small mass of living tissue which becomes 

 the adult, leaving the larva to perish. We know, in both groups, 

 of hermaphrodites and of disecious species, and now we have ad- 

 ded a viviparous form of echinoderm, such as was previously 

 observed in some nemertiau worms. We have yet to discover 

 among tlie echinoderms the various modifications of a sexual re- 

 production, by pseudova, fission, or true parthenogenesis; the 

 first two of which methods (especially fission) are so well known 

 among worms. — Quart. Journ. f)f Science, Oct., 1868. 



ELASMOSAURUS PLATYURUS : A NEW FOSSIL MARINE REPTILE. 



In the Proceedings of the Academy of Sciences, of Philadel- 

 phia, 1868, Prof. Cope has described a new large enaliosaurian 

 reptile, discovered in Kansas, by Dr. T. H. Turner. Tlie remains 

 consisted of over 100 vertebras, the greater part of the pelvic and 

 scapular arches, many portions of ribs, and part of a muzzle witli 

 teeth. Though related to the Plesiosaurus and its allies, it diff'ered 

 in important features ; such as the absence of diapophyses on the 

 caudal vertebrae, and the presence of inferiorly directed plate-like 

 parapophyses which took the place of the usual chevron bones in 

 the same position ; also in the presence of chevron-like bones on 

 the cervical vertebrae, and in some details of the pelvic and scap- 

 ular arches. It differed from Cimoliosaurus and Brimosaurus 

 (Leidy) in the absence of diapophyses on the lumbar vertebrae ; 

 those of the dorsals originated from the centre, and not from the 

 neural arch. It differed from Plesiosaurus in the enormous length 

 of the tail, and the relatively shorter neck. The total length of 

 the vertebral colunm sent was 31 feet, 10 inches, as follows : cau- 

 dals, 18 feet 10 inches; dorsals, 9| feet; cervicals, 3i feet; adding 

 for missing cervicals and cranium, 2^ feet, we have a total of 

 about 34i feet, and probably 38 feet. The caudals had very com- 

 pressed centres, and elevated neural and haemal laminae, and were 

 unusually elongated ; neural arches everywhere co-ossified to the 

 column. The name is derived from the caudal laminae, and the 

 great plate bones of the sternal and pelvic regions. 



It was a marine saurian, progressing rather by the tail than by 

 its paddles. The teeth and muzzle shovved it to be an ally of 

 plesiosaurus ; the former were cylindrical, implanted in very deep 

 sockets, and with a very small pulp cavity ; the exposed surface 

 closely and sharply striate to the narrowly acuminate tip. The 

 beds were argillaceous, with much gypsum, the latter coating the 

 bones ; the age was cretaceous, perhaps the upper middle. 



[The elongated form of this marine saurian comes nearer co the 

 described modern sea-serpent than any other ; it may have dis- 

 appeared, actually or apparently in the tertiary, to reappear at 

 27* 



