ZOOLOGY. 577 



Adaptation to environment of Trematods. 



Professor Ercolani bas published a useful summary of facts in the 

 development of Trematods related to adaptation for environment. (1) 

 The succession of phases of development is not always the same in all 

 Trematods, some leaving the eggs as ciliated embryos requiring water, 

 and others as non-ciliated ones, developing in terrestrial gastropods ; (2) 

 the different phases of development are not the same for all encysta- 

 tiou, e. g.j being sometimes omitted; (3) a special form of scissiparous 

 generation may occur e. g., in the racemose sporocysts where certain 

 living parts (as in Polyzoans and Hydroids) are connected by atrophied 

 stolons ; (4) the direct conversion of the tail of a cercaria into a nurse 

 sometimes occurs; (5) encystatiou may not only be normal, but also 

 accidental or abnormal. 



It is far from true that there is a determinate relation between Trem- 

 atods and Mollusks, and that the latter have only one species each; 

 Bythinia tentaculata, e. g., has as many as twelve different species of 

 cercariae. (J. E. M. S., (2) v. 3, p. 784, from Arch. Ital. Biol., v. l,p. 

 439-453.) 



NEMATELMINTHS. 



DrascheCRich. von). Revision der in der Nematoden-Sammlung des k. k. zool. Hof- 



Cabipots befindlichen Original Exemplare Diesing's und Molius. Mit. 4 Taf. 



Verhandl. k. k. zool. bot. Ges. Wien, 1882, pp. 117-138. 

 Fourment (L.). Sur la vitalit6 des Dichines enkyst^es dans les viandes salves. 



Cornpt. rend. Ac. Sc. Paris, t. 94, p. 1211-1213. 

 M^gnin (P.). Sur de petits Helminthes aganies ekyst^s qni peuvent dtre confondus 



et qui 1' ont 6t6 avec la Trichina Spiralis. Avec 3 pi. Bull. Soc. zool. France, 6. 



Ann. p. 189-198. 

 M6gnin (P.). Sur 1' organisation de la bouche des Dochmius ou Ankylostomes, Apro- 

 pos de parasites de ces deux genres trouv^s chez le chien. Compt. rend. Acad. 



Sc. Paris, t. 94, p. 663-666. 

 Orl-ey (L.). Report on the Nematodes in the possession of the British Museum, with 



a review of the classification of the order. With 1 pi. Ann. & Mag. of Nat. Hist., 



(5,) V. 9, p. 301-318. 

 Orley (L.). Monographic der Anguilluliden. Mit. 7 Taf. Term^sz Fiizetek, v. 4, 



p. 154-177 (Deutsches Anszug d. ungar. geschriebenen Arbeit., p. 16-150). 

 Schnlthess (Wilhelm). Beitrage zur Anatomie von Anlcylostoma duodenale (Dubini)= 



Dochmius duodenalis (Leuckart). Mit 2 Taf. Zeitschr. f. wiss. Zool., 37 Bd., p. 



163-220. 



The Nematoid Worms. 



Dr. L. Orley has recently studied the Nematoids in the British Museum 

 and has come to the conclusion that there are three •' suborders " although 

 "there are perhaps few orders in which so continuous a series of forms 

 exists as in the Nematodes." His views as to the question of relationship 

 between parisitism and non-parisitism and classification may be gleaned 

 from his daignosis of the several groups. 



1. The Nematentozoa are " thread worms completing their early 

 «tage in the free condition, their maturity as parasites in the bodies of 

 H. Mis. 26 37 



