ZOOLOGY AND BOTANY^ MICKOSCOPY, ETC. 729 



derived from a Peripafus-like ancestor. The carboniferous Myriopod 

 Euplioheria, as described by Scudder, presents arrangements which are 

 found during the development of Julus. The Archipolypoda have the 

 dorsal part of the body ring, which is now single, distinctly divided. 

 It is probably best to regard each part of the so-called double-segments 

 as a segment complete in itself, but joined to its fellow by the fusion of 

 two dorsal plates. It seems likely that the Chilopods and Diplopods 

 branched off from a common ancestor at some period not very long 

 before the appearance of the Archipolypoda, and that both are remotely 

 descended from some Peripatus-like stock. 



S. Araclinida. 



Anatomy of Gamasidae.* — Herr W. Winkler has investigated the 

 structure of Gamasid^, especially of the genera Gamasus and Uropoda. 

 In regard to the general segmentation of the body, he regards the 

 boundary of the " capitulum " as marked by a chitiaous ridge which 

 extends directly in front of the first pair of legs. As to the mouth 

 appendages, the chelicerfe are equivalent to the mandibles, for their 

 nerves come from the sub-oesophageal ganglion, from a portion distinct 

 from the rest of the mass. The maxillae, lower lip, and tongue are 

 carefully described, and their relations and modifications discussed. In 

 discussing the other appendages, he emphasizes, against Megnin and 

 Pagenstecher, that the first pair are not labial palps, but true legs. The 

 terminations are very fully described. 



The cuticle with its plates and layers, the interstitial connective 

 tissue, the musculature like that of Tyroglyphidte, the nervous system, 

 and the sensory bristles are then briefly described, and the author 

 discusses the richly-branched tracheal system. The actively pulsating 

 heart lies in the anterior half of the abdomen, above the posterior end 

 of the mid- gut. It is one-chambered, short and broad, with two valved 

 openings and a long aorta. It may be regarded as a reduction from the 

 heart of Araneidae, and betv/een the two the hearts of Chernetidee and 

 Phalangidfe may be placed. 



In the alimentary system Herr Winkler describes the pharynx with 

 its six pairs of muscles, the narrow CESophagus, the wide mid-gut with 

 six sacs and hepatic glands, the simple glandular hind-gut, and the 

 vesicular rectum. The excretory organs are certainly homologous with 

 Malj)ighian vessels. They consist of two separate long tubes, which 

 open along with the hind-gut into a capacious collecting bladder, which 

 is really part of the excretory and not of the alimentary system. Finally, 

 the author describes at length the male and female reproductive organs, 

 and makes a few notes on development. 



6. Crustacea. 



Intestine and Digestive Glands of Decapods.f — Prof. G. Cattaneo 

 has investigated the histology of the intestine in Decapoda, and the 

 function of the associated glands. In the intestine of Palinurus vulgaris 

 he distinguishes and describes seven layers — the chitinous cuticle, the 

 cylindrical epithelium, the connective layer, the longitudinal muscles, 

 the radial muscles, the circular muscles, the external connective tissue. 

 Many types are discussed. The histological part of the research evi- 



* Arbeit. Zool. Inst. Univ. "Wien, vii. (1888) pp. 317-54 (1 pi.), 

 t Aicb. Ital. Biol., ix. (1888) pp. 255-G6. 



