8 



1772 Voyage en California pour Pobservation dn passage do Ve"nus sur le disque dn 

 soleil, le 3 juin 1769; contenant les observations de ce phenomene et la dis- 

 cription historique de la route de 1'auteur a travers le Mexique. Par feu M. 

 Chappe d'Auteroche, . . . R6dige~ et publi6 par M. de Cassini fils . . . 

 A Paris: chez Charles- Antoine Jombert. MDCCLXXII. [4, half-title, 

 title, 170 [2] pp., plan, and 2 pi. Sabin.] 



[Translated as follows:] 



A Voyage to California, to observe the Transit of Venus. By Mous. Chappe 

 d'Auteroche. With an historical description of the authors route 

 through Mexico, and the natural history of that province. Also, a voyage 

 to Newfoundland and Bailee, to make experiments on Mr. Le Roy's time 

 keepers. By Monsieur de Cassini. London: printed for Edward and Charles 

 Dilly, In The Poultry. MDCCLXXVIII. [6 C , 4 p. 1., 315 pp., with "plan 

 of City of Mexico".] 



Extract of a letter from Mexico addressed, to the Royal Academy of Sci- 

 ences at Paris, by Don Joseph Anthony de Alzate y Ramyrez, now 

 a correspondent of the said academy, containing some curious particu- 

 lars relative to the natural history of the country adjacent to the City 

 of Mexico, pp. 77-105. 



[It is undoubtedly this work that is meant in the statement that has so largely gone the 

 rounds of the periodical press, to the effect that the Calilbrnian viviparous fishes were ob- 

 served driving the voyage for the observation of the transit of Venus to Lower California, 

 1769. A perusal of the accounts given, however, renders it evident that the fishes in ques- 

 tion were not Etabiotocids but rather Cypriuodontids, probably of the genus Mollienesia. 

 The account by Don Alzate (pp. 89-91) is as follows: 



" I send you some viviparous scaly fishes, of which I had formerly given you an account. 

 What I have observed in them this year is' If you press the belly with your fingers, you 

 force out the fry before their time, and upon inspecting them through the microscope yon 

 may discern the circulation of the blood, such as it is to be when the fish is grown up.' If 

 you throw these little fishes into water, they will swim as well as if they had beeii long 

 accustomed to live in that element. The fins and tail of the males are larger and blacker 

 than those of the females, so that the sexjs easily distinguished at first sight. These fish 

 have a singular manner of swimming ; the male and the female swim together on two par- 

 allel Hues, the female always uppermost and the male undermost; they thus always keep 

 at a constant uniform distance from each other, and preserve a perfect parallelism. The 

 female never makes the least motion, either sideways or towards the bottom, but directly 

 the male does the same." 



To this account is added a foot-note (p. 90) containing the following additional informa- 

 tion: 



"Don Alzate has sent those fishes preserved in spirits; their skin is covered with very 

 small scales ; they vary in length from an inch to eighteen lines, and they are seldom above 

 five, six, or seven lines in the broadest part. They have a fin ou each side near the gills, 

 two small ones under the belly, a single one behind the anus, which lies between the fin 

 and the single one ; the tail is not foi ked ; lastly, this fish has a long fin on the back, a 

 little above the fin, which is under the belly. 



""We know of some viviparous fishes in our seas, such as loach, &c. most of these have 

 a smooth skin without any scales. The needle of Aristotle is viviparous, and yet covered 

 with broad and hard scales, I have caught some that had young ones still in their womb. 

 As to these viviparous fishes, it is a particular and new sort, and we are obliged to Don 

 Alzate for making us acquainted with it. It breeds in a lake of fresh water near the City 

 of Mexico." 



This is, so far as known, the earliest notice of the viviparity of Cynrinodontids. The 

 mode of consorting together (exaggerated in the account) is common to a number of rep- 

 resentatives of the family, and is alluded to by Prof. Agassiz in a name (Zygonectes, i. e. 

 swimming in pairs) conferred on one of the genera of the family.] 



1 8O8 Piscium Camtschaticorum [Tcrpufc] et [ Wachnja']. Descriptiones et icones 

 auctore [W. G.] Tilesio. D. 26 Octobri 1808. Conventui exhib. die 2 Nov. 

 . 1808. < M6m. Acad. Sci. Pe"tersb., v. 2, pp. 335-375, 1810, viz : 



I. Hexagraramos Stelleri, Rossis Terpuc dictus novum genus piacium 

 Caintschaticorum. pp. 335-340, tab. 15. 



