1895.] HIDRACHNIJ) fOUND IN COBNAVALL. 205 



Bibliography of the principal Treatises on the Internal Anatomy of 

 the Hydrachnidce and some allied Families referred to in the 

 foregoing paper. 



Cbonebebg, a. " On the Anatomy of Eylais e,vtendens (Miiller). 



With observations on aUied forms." In Russian, in ' Nacb- 



richten Gesellscb. der Freunde der Xatiirkunde.' Moscow, 



1878. A short summary in Grerman, called " Ueber den Bau 



der Hydrachniden," in Zool. Anzeiger, 1878, Nr. 14, p. 316. 

 . " Ueber den Bau A^on Trombidium." Bull. Soc. Nat. de 



Moscou, 1879, part 2, p. 234. 

 Henkin, H. " Beitrage zur Anatomie, Entwickluugsgeschichte 



and Biologie von Trombidium fidiginosimi, Herm." Zeitschr. 



flir wiss. Zool. Bd. xxxvii. (1882) pp. 554-663. 

 Nalepa, a. " Die Anatomie der Tyroglyphen," Sitzb. d, k. Akad. 



d. Wissensch. Wien, Bd. xc. Abth. 1, p. 198 (1884); Bd. xcu. 



Abth. 1, p. 116 (1885). 

 Pagenstechee, H. a. " Beitrage zur Anatomie der Milben." 



Heft I. Leipzig, 1860. 

 ScHAUB, R. VON. " Ueber die Anatomie von Hydrodroma (C. L. 



Koch). Ein Beitrag zur Kenntniss der Hydrachniden." 



Sitzb. d. k. Akad. d. Wissensch. in Wien, Bd. xcvii. Abth. 1, 



p. 98 (1888). 

 . " Ueber marine Hydrachniden, nebst einigen Bemerkungen 



uber Midea (Bruz.)." Ibid. Bd. xcviii. Abth. 1, p. 163 (1889). 



EXPLANATION OF THE PLATES. 



Letteeing. 



A. Anua (so-called). It is really the orifice for the discharge of the excretory 



organs only, not apparently of the alimentary canal. 

 ae. Air-chamber ; this is the hollow within the chitinous sigmoid piece. 

 ap. Anal plate. 

 ar. Areolations in the larger chitinous plates. 



B. Endoskeletal " chitinous bridge " forming the floor upon which the 



mandibles run, and also forming a rigid base of attachment for 

 the outlet of the salivary ducts and for the ligament from the 

 sigmoid piece. 

 br. Brain. 



C. Cuticle. 



ch. Chitinous bar forming a base of attachment for muscles. 



cc. Clear yellow chitin. 



c<B. Anterior (azygous) cascum of the ventriculus. 



cm. Chitinous external tunic of genital sucker, convex exteriorly (meniscus- 

 shaped). 



cp. Chitinous areolated plates in the cuticle (larger kind). 



cs. Chitinous plates in cuticle more finely and regularly perforated (smaller 

 kind with hair). 



ct. Connective tissue. 



B. Common duct of the three salivary glands (so-called) on one side of the 

 body, viz., the quadrate, the reniform, and the tubular salivary 

 glands. 



dh. Bell-shaped mouth, of same. 



de. Ductus ejaculatorius. 



