INVEKTEBRATA, CRYPTOGAMIA, MICROSCOPY, ETC. 425 



but only that it has partly tho same functions; nor must it be 

 supposed that tho gland produces either tryjjsin or pepsin. 



Gastric Apparatus of the Brachyura.* — Dr. Nauck gives a table 

 of the terminologies applied by authors to the different parts or 

 processes which make up tho complex gastric mill of the higher 

 Crustacea ; these have each certain advantages and certain disadvan- 

 tages ; the one now proposed is perhaps superior in being altogether 

 based on topographical relations. It will not be necessary to give the 

 whole of the table, but in face of the interest which has been excited 

 by the publication of Professor Huxley's work on the Crayfish, we 

 give the synonymy of the parts named by these two authors. The 

 cardiac ossicle of Huxley is the anterior super omedi an of Nauck, the 

 pterocardiac ossicle tlie anterior superolateral, the urocardiac i)rocess 

 is the median superomcdian, the prepyloric ossicle is tho posterior 

 superomedian, the zygocardiac ossicle is the median superolateral, the 

 inferolateral tooth is the median " twixt-piece," and the cardiopyloric 

 valve is tho inferomedian.^ 



After an elaborate account of these structures in a number of 

 genera and species, the author points out that althougli it is im- 

 possible to find in the characters of tho gastric apparatus of the 

 Brachyura any means by which forms may bo specifically or 

 generically separated, yet it is possible to see that, by its aid, 

 they may be divided into the Heterodontea and Cyclodontca ; in 

 the former the median teeth never consist of simple lamellfe, and 

 the superolateral cardiac pieces lie in front of the superomedian ; in 

 the latter the median teeth (with one exception) aro formed of 

 lamella}, and the anterior superolateral pieces lie behind the supero- 

 median. An investigation into the course of development of the 

 cardiac portions of the mill seems to show that the Gelasimida, 

 Pinnotherida, Portunida, and Cancrida are the oldest rei)resentatives 

 of the Brachyiira, and this result is in accordance with what is 

 taught by pala^ontological data. An ojjportunity is taken to describe 

 some new genera and species, and tho facts are illustrated by a care- 

 fully drawn plate of 31 figures. 



Reproduction of the Isopod Crustaceans.^ — The earlier papers 

 of Dr. Schobl contain several new propositions in Isopod anatomy 

 which are now generally accepted, with one exception — Lis discovery 

 of the female generative openings and of the receptacula scminis. Since 

 many competent observers had completely failed to find any trace of 

 them in the place where he had described them, the hypothesis sug- 

 gested itself that at certain seasons the 02)euiug8 may be present, at 

 others not. 



By keeping as many as 10,000 specimens of Porcellio scaler and 

 otlicr Oniscidie, in largo glass vivaria containing layers of moistened 

 sand, bark, and moss, ho lias now been able to study an abundance of 

 8j)ocinieiis at all pericxls of the year, and thus fairly test tho validity 

 of his explanation. From January to April one easily finds tho minute 

 * ' /iiiitschr. wins. Zool.,' xxxiv. (1S80) p. 1. 

 t ('{. Hiixl.y, 'CmyliHh.' fi-,'. 9. 

 : • Aivli. IMikr. Aiiat.,' xvii. (187D) j). 125 (2 plutos). 



VOL. m. 2 F 



