Chap. II. CLASSIFICATIONS OF ACALEPIIS. 135 



Were not Latreille the first entomologist of all ages, and had he not shown himself 

 a master in describing species, characterizing genera, defining natnral families, and 

 improving generally the classification of Insects, it would hardly be worth our 

 while to consider his attempt at classifying the Acalephs. But this attempt of 

 his may serve as a warning against the temptation, too frequently indulged by 

 eminent men, to express opinions upon matters with which they are not familiar, 

 or to cover their ignorance by an easy display of high-sounding but empty words. 

 On looking at the diagram of Latreille's classification of the Acalephs, it might 

 seem, at first sight, that he presents in it a new and original arrangement of 

 these animals. The names Poccilomorpha and Cijdomorplia, with which he designates 

 the two orders into which the class is divided, are certainly new to science, but 

 they are utterly useless and superfluous, inasmuch as they neither represent a new 

 view nor a new comljination in the classification of these animals, and are in no 

 Avay better than those which had already been proposed l^y Lamarck and Cuvier 

 for the very same division. The limitation of the families is, if possible, worse, 

 and the names apphed to them are liable to the same objections as those of 

 the orders. 



CLASSIFICATION OF LATREILLE, 1825. 



The views of Latreille upon the affinities of the Acalephs were published in his " Families natu- 

 relles du Regne animal," Paris, 1825, 1 vol. 8vo. Adopting the class of Acalephs as circumscribed by 

 Cuvier, he divides them into two orders and six families. 



1st Order. Poecilomorpiia, corresponding to the Radiaires Mollasses Anomales of Lamarck, exclusive 

 of Lucernaria. 



1st Family. Ciliata: Beroe, Callianira, Cestuni, Dijihyes. 



2d Family. Papyraeea : Porpita, Velella, Noctiluca. 



3d Family. llydrostatica : Physalia, Physophora, Rhizophysa, Stephanomia. 

 2d Order. Cyclomoupha, corresponding to the Radiaires Mollasses Medusaires of Lamarck. 



1st Family. Monocotyla : Medusa, ^quorea, Foveolia, Phorcynia. 



2d Family. Polycotyla : Cyanoa ; Rhizostoma. 



3d Family. Acotyla : Lyranorea, Favonia, Geryonia ; Berenice, Eudora, Carybdea. 



The families of the Cyelumorpha are entirely artiticial, and in no way express the natural affinities 

 of the animals; and the families of tlie Poecilomorpha are borrowed from other writers, — the name of 

 Beroes, proposed by Goldfuss, being changed to Ciliata, that of Porpita to Pa-pyracea, and the name 

 Hijdrostalica retained from Cuvier. The Hydroids are referred partly to the class of Polyps, in the tribe 

 Va^iniformia, and partly to his class Ilelianthoidea, which embraces Actinia, Zoanthus, and Lucernaria. 



The animals belonging to the class of Acalephs are so peculiarly delicate, so 

 difficult to handle, and so perishable, that the circumstances under which they may 

 be studied, form almost as important an element in their investigation, as the aptitude 



