140 ACALETHS IN GENERAL. Part I. 



Lesson is one of the naturalists who had the best opportunities for observing 

 the Aealephs. Emljarked with Garnet on Ijuard the Coquille, he made the voyage 

 around the world with Captain Dupcrrey, and prepared many beautiful illustrations 

 of Aealephs for the zoological atlas of that expedition. On his return he made 

 the most extensive eollection of drawings of these animals ever brought together, 

 with the intention of publishing a complete Iconography of this class ; but the 

 magnitude of the undertaking prevented its execution, and nothing was published 

 liut a " Prodrome d'une Monographie des Meduses," with a short notice of two 

 hundred and thirty-seven species, arranged in seventy genera. Some of the plates 

 were afterwards introduced in the " Centurie Zoologique," and the text appeared, 

 in 1843, among the " Suites Ti Buffon," under the title of "Ilistoire naturelle des 

 Zoophytes, Acalephes." To this day, this is the chief work of reference for the study 

 of the Aealephs ; Ijut it is much to be regretted that it is neither methodical in 

 its plan nor critical in its details. It is rather a comitilation than an original work ; 

 and 3'et it contains much that cannot be found elsewhere. Edw. Forbes has the 

 following just but severe criticism of this extraordinary production: "This Avork is 

 one of the most useful, and yet one of the most inovoking, in its department of 

 Natural History: useful, because it brings together, vcrhatim, every thing that has 

 been written upon the Medusae in France ; provoking, because every attempt in it 

 at an arrangement or digest of the matter so collected serves only to make the 

 obscure more obscure and the crude more crude. It is executed without any 

 judgment, though with considerable industry. Of what has been done outside of 

 France it is a most imperfect account."^ 



CLASSII-'ICATION OF LESSON, 184.3. 



Like his iiredeoessors, Lesson does not allude to the Hydroids in connection witli the Aealephs. 



1st Family. Beroide.e. 



1st Division. CUiohranchi'S oi- Iripteres. 



1st Tril)e. Cestoideiv : Cestinn, Lemniscus. 



2d Tribe. Callianir;e : C'allianira, Chiaia, Poly])teni, Mnemia, Bucephalon, Bolina. 



.3d Trilie. Leucothoeaj: Leucothoea. 



4th Trilje. Calynimeiv : Calynnua, Eueliaris, Aleinoe, LeSucuria, Axiotima. 



5th Tribe. Neisid;e: Neis. 



Cth Tribe. Oeyroe;v : Oiyi'oe. 



7th Tribe. Cydippa? : Mertensia, Anais, Eschscholtzia, Janira, Cydippe. 



8th Tribe. Beroa» : Beroe, Idya, Medea, Cydalisia, Pandora. 

 2d Division. Acils. 



False Beroids : Galeolaria, Dolioluni, Rosacea, Suleuleolaria, Praia, Noctiluea, Appendicularia. 



' Eiiw. FoiiBES. A monograph of the British Naked-eyed Medusa', London, 1818, p. 08. 



