512 Scientific Intelligence. 



SCIENTIFIC INTELLIGENCE. 



I. GEOLOaY AND MiNEEALOGY. 



1. The Appendages, Anatomy, and Relationships of Trilohites; 

 by Percy E. Raymond. Mem. Connecticut Acad. Arts and Sci., 

 vol. 7, 169 pages (quarto), 11 pis., 46 text figs., 1920.— The sud- 

 den death of Professor C. E. Beecher in 1901 left unfinished his 

 studies of the ventral anatomy of trilohites, and it is fitting that 

 one of his students, Professor Raymond, of Harvard, should take 

 up the work and bring it to a successful conclusion. The splendid 

 memoir which results, dedicated to Beecher and having a portrait 

 of him as its frontispiece, contains many of his drawings and 

 photographs illustrating the ventral anatomy of the trilohites, 

 here reproduced for the first time. 



The memoir consists of four parts. In Part I are described in 

 detail the ventral appendages of nine American genera : Neolenus, 

 Isotelus, Ptychoparia, Kootenia, Ceraurus, Cahjmene, Acidaspis, 

 Cryptolithus, and Triarthrus. Excellent pen and ink restorations 

 are presented of Neolenus, Isotelus, Triarthrus, Ceraurus, and 

 Cryptolithus. AYith the exception of the antennules in all of the 

 genera, and the caudal cerci known only in Neolenus, all the 

 appendages are biramous. These rami always consist of endop- 

 odites and exopodites, and tlie author sees no other appendages 

 like those described by Walcott in Neolenus and Calymene. The 

 inner appendages (endopodites) functioned as locomotory organs, 

 either for crawling, swimming, or burrowing, the particular 

 method varying with the species. Doctor Raymond considers the 

 exopodites to have functioned primarily as gills, and only second- 

 arily as swimming organs, and suggests that where the pygidium 

 is large, it served as a swimming organ. He agrees Avith Beecher 

 in the latter ■ s homolog^^ of the cephalic appendages with those of 

 the higher Crustacea, the first pair of biramous appendages being 

 homologous with the antennge, and the other three pairs repre- 

 senting the mandibles and the first and second pairs of maxillae. 



In Part II are considered the internal structures and habits of 

 trilohites. Except for the eyes, data are rather scanty. The 

 intestinal cavity is thought to have been enlarged beneath the 

 glabella and thence to have passed straight backward beneath 

 the middle lobe of the test. Muscles, nervous system, various 

 glands, heart, etc., are discussed to the extent the structures are 

 known.. The " median • ocellus " or '' dorsal organ" of the 

 glabella of many trilohites is interpreted as the point of attach- 

 ment of a ligament supporting the heart. The habits of life are 

 considered with respect to locomotion, food, and feeding, and it is 

 found that in maturity trilohites were adapted to planktonic, 

 nectonic, and benthonic environments, according to species. It 

 is suggested that in the early stages of their racial history the 

 trilohites were carnivorous, but that even before Middle Cam- 



