ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 305 



southern regions by species of two distinct genera, Decalopoda and 

 Pentanymphon. 



2. The genus Decalopoda is represented by two species, D. austral is, 

 common off the South Shetlands, and D. antarctica, found by Charcot 

 nearer the pole. 



3. The genus Pentanymphon is widely distributed around the Ant- 

 arctic continent, and the known species, P. antarcticuni, becomes more 

 abundant as one goes farther south. 



4. The octopod Pycnogonids of the genera Gordylochete and Ammo- 

 thea are abundant in the south, as in the north. The Ammotheidse are 

 especially common, and none of their representatives are of large size. 



Classification of Pantopoda.* — Wl. Schimkewitsch discusses this in 

 detail, but we cannot do more than refer to a few points. The genera 

 Nymphopsis Haswell, Eurycyde Schiodte, Ammothella Verrill and Cole, 

 and 'Dohrn's Ammothea appendiculata, are near the hypothetical primitive 

 ancestor which he calls Oronymphon. He thinks that Pentanymphon 

 and Decalopoda (which have five pairs of legs) may be regarded as 

 neotaenic forms of genera with the usual four pairs. The chief part of 

 the paper illustrates what the author calls the " periodicity " of types : 

 thus there are forms with a 3- jointed first appendage, and with 10, 9, 

 8, 7, or fewer joints in the second appendage ; there are forms with a 

 2-jointed first appendage, and with 10, 9, 8, 7, 6, 5, or fewer joints in 

 the second appendage. So the author constructs tables which recall the 

 Periodic Law in chemistry, and in any case illustrate the gradualness of 

 morphological changes. 



Structure and Position of Tardigrada.f— Albert Basse has been 

 able to overcome the difficulties in the way of sectioning these small 

 animals, and gives an account of the integument, alimentary system, 

 blood, musculature, nervous system, and gonads, with especial reference 

 to species of Macrobiotus. The author regards the Tardigrada as near 

 the base of the Arthropod stem. With Tracheata they are united by a 

 number of characters : the clawed appendages (jointed in Lydella, with 

 at least one joint in Macrobiotus hufelandi), the presence of Malpighian 

 tubules, the nature of the exoskeleton, musculature, nervous system, and 

 intestinal glands, the presence of antennary nerves, the probably paired 

 nature of the genital apparatus, and the differentiation of the ovary into 

 germinal and nutritive portions. 



Chitin in Carapace of Pterygotus osiliensis.f — Otto Rosenheim 

 finds that the general behaviour of the substance of the carapace of this 

 Silurian Eurypterid towards acids and solvents is such, that it is probably 

 chitin ; and this is confirmed by the fact that, after such treatment, it 

 yielded on hydrolysis with concentrated hydrochloric acid, a strongly 

 reducing substance which is presumably glucosamine. 



€ - Crustacea. 



Hermaphroditism in Crayfishes.§ — William P. Hay notes that some 

 degree of hermaphroditism has been recorded in Homarus vidgaris, 



* Zool. Anzeig., xxx. (1906) pp. 1-22 (3 tables), 

 t Zeitschr. wiss. Zool., lxxx. (1905) pp. 259-81 (2 pis. and 1 fig.), 

 t Proc. Roy. Soc, lxxvi.. series B (1905) No. B 511, pp. 398-400. 

 § Smithsonian Misc. Collections, xlviii. (1905) pp. 222-8 (1 fig.). 



June 20th, 1906 x 



