INVERTEBRATA, CRYPTOGAMIA, MICROSCOPY, ETC. 717 



Organization of the Phronimida.* — After some remarks on the 

 systematic position aud the more important characters of this some- 

 what abnormal group of the Ami)lupoda, together with a diagmjsis of 

 the new genera Plirouimoims and Parajphronima, Professor Clans 

 enters into the discussion of the structure and organization of the 

 group :— 



Appendagea. — The antenn33 are particularly interesting, inasmuch 

 as it is ordinarily stated that Phronima is provided with only one 

 l)air. Starting, as an examination of the earlier stages allows us to 

 do, witli tlie sim2)le appendage of two joints, we find, in a very early 

 stage of development, that the cylindrical antenna contains in its 

 terminal joint an aggregation of cells, which become differentiated 

 into a small ganglion, and that a seta and an olfactory filament ai)pcar 

 at its tip; later on there appears a second filament, and, as the terminal 

 joint increases in length, there appear a third and fourth ; next we 

 see that in the young female of Phronima the terminal joint increases 

 considerably, and there appear, in pairs, a number of new olfactory 

 filaments, while in many other Hyperida there are differentiated one 

 or two short intermediate joints and a terminal rudimentary flagellum. 

 In the young male the terminal joint becomes much thicker, and the 

 olfactory filaments hjse their terminal position ; two joints become 

 intercalated, and the terminal piece commences to form an appended 

 fiagellum ; in the adult of all the male Phronimida there is a many- 

 jointed long flagellum, the anterior surface of which is provided with 

 a thick tuft of long hair-like olfactory filaments. 



The second antenna is not altogether absent in the female, inas- 

 much as its basal joint is always present, although indeed it is so 

 closely fused with the integument as merely to form an elevation 

 provided with a feebly developed seta, or a more strongly developed 

 spine. The antennary character of the elevation is spoken to by the 

 presence on it of the orifice of the duct of the antennary gland, whicli 

 corresponds to the " green gland " of the crayfish. 



The mouth organs agree generally with those found in other 

 Hyperida ; the mandibles and paragnathi form a distinct oral atrium, 

 aud groups of glands, which probably have a salivary function, arc 

 developed in tlie maxilke and maxillary appendages. On the thoracic 

 appendages the joints appeared to be reduced to the coxa, but other 

 pieces can be made out ; in the fifth pair the arrangement becomes 

 more complicated, aud an elaborate glandular system may bo seen 

 in the appendages. 



Alimentary Canal. — The salivary glands already mentioned are 

 fovmd to be complexes of four glandular cells with long efferent 

 ducts, which are partly placed around the oesophagus, and partly in 

 the jaws ; they secrete ferments which act on starch and albumen. 

 The enteric canal contains no glandular cells ; its muscular and 

 complicated oesophagus leads into a stomach which is provided with 

 two secondary pouches ; there arc two hepatic tubes, and the narrow 

 intestine ends, in the sixth abdominal segment, by a short rectum. 

 The short tubes attached to this last portion, which have been ob- 

 * ' Alb. Zool. Inst. Wicn ' (Glaus), ii. (1870) art. 2. 



VOL. II. 3 B 



