INVERTEBRATA, CRYPTOGAMIA, MICROSCOPY, ETC. 633 



slightly different. The rectum is a subspherical muscular sac, which 

 at regular intervals contracts so as to leave a linear cavity (along the 

 long axis of the animal), and immediately dilates, sucking up the 

 water from without. An anal respiration, such as that of Cyclops, is 

 found widely among Crustacea — even those which have well-developed 

 gills like Asfacus, which is one of the highest forms. It has been 

 demonstrated in Phyllopoda and Cladocera, and is probably the exclu- 

 sive mode in Leptodora, as shown by Weismann. That it is therefore 

 primitive, and should be expected to occur in the primitive, or at least 

 very generalized group of the Copepoda, is an obvious deduction. 

 Hence the author anticipates that the homoiomorphic zooea larvaD of 

 the Decapoda will prove to have this same mode of respiration. 



If there bo any connection between Rotifers and NauijUus, it is 

 easy to make out the origin of the arrangement in the latter. The 

 ciliated funnels and lateral canals of the former can only be of service 

 when there is a thin unchitinized anterior surface through which 

 water can transude into the ccelom ; by the extension of chitinization 

 over the whole surface, these organs lose their function and abort, 

 while the cloacal " contractile vesicle " takes on an inspiratory as 

 well as an expiratory function, and becomes more or less confounded 

 with the rectum, from which probably, even in Eotifers, it takes origin. 



Here must be noticed the wide diffusion of anal respiration in 

 aquatic insect larvfe (alternate inspiration and expiration by the 

 pumping movements of the rectum). This would point to a common 

 origin with Crustacea. 



A list of the groups in which anal respiration is made out may bo 

 added : — 



Vebmes : 



Eotifera. 



Gephijrca. 



Oliijochwto-Limicola. 



ECHINODEEMATA : 



Ilolothiiroidea. 

 Arturopoda : 



Crustacea (f^cncral). 



Insccta (most aquatic larvas). 

 MOLLUSCA : 



Dentalium, 



Parasitic Corycseidse.* — Dr. Delia Vallo makes some contributions 

 to our knowledge of the anatomy of the genus LirliomoJgus, somo 

 species of which are parasitic on Actinia.', while others are found on 

 Mollusca, Worms, or Tunicates. He describes as new L. ndin'uv, 

 li. ftcroulis (on Pleroklcs fipinulnsus), and L. chromodo^'idis, of which 

 the female is alone known. IIo forms a now genus, Anthcssus, for 

 some forms allied to Lichomohjus, the sjiecies of which, A. Solvcurli, 

 and A. plcurohranrhitc arc distinguished by the characters of their 

 mouth-organs. 



Parasite of the American Blue Pike.t — Professor D. S. Kellicott 

 describes a new species of Anjidm found on tlie blue pike {Stizostelhiiim 



* ' Jlitth. Zool. Stat. Neapfl,' ii. (ISSO) p. S'X 



t 'Am. Jouni. Micr.,' v. (1.MS0) p. ^[i. Kio ' Naturo,* xxii. (ISSO) p. 111. 



