ZOOLOGY AND BOTANY, MICEOSGOPY, ETC. 431 



Sexual Dimorphism in Ophiacantha vivipara.* — R. Koehler finds 

 that this Ophiuroid, collected by the Cape Horn Expedition, shows a 

 remarkable sexual dimorphism. The males have 5 arms and the females 

 always more (6-8). In one specimen he found a Mtjzostoma, which 

 may be new. The only similar case is that reported by Lyman Clarke f 

 of a Myzostoma on Ophioceras and on Astroceras pergamena. 



Eyes of Deep-sea Starfish. | — W. Meurer has studied these in a 

 number of forms, with the following results. Eyes were found in eight 

 species belonging to the families Archasteridse, Astropectenidge, and 

 Pentagonasteridse, whose depths ranged from 628-3667 m. Eyes 

 were absent in the two typical deep-sea families Zoroasteridae and 

 Porcellanasterida3, with depth ranges from 468-5868 m. Pseudar chaster 

 pulcher from 702 m., and Dipsacaster sp. from 791 m., possessed 

 remarkably large eyes ; Plutonaster spatuliger from 1895 m., and 

 P. granulosus from 1700 m., showed a partial disappearance of the 

 eyes. Cheiraster agassizii from 1895 m., an eyeless form, has a well- 

 formed eye-pad, and other types show this structure more or less 

 degenerate. 



■^o^ 



Classification of Echinoids.§ — Fred Yles discusses the taxonomic 

 value of the maxillary apparatus. Is there a brusque separation between 

 " gnathostome " and " atelostome " forms ? Is there any hint of a 

 rudimentary state of the masticatory apparatus ? May the remains of 

 the perignathic girdle be represented, for instance, by the small 

 apophysis at the left corner of the mouth of Spatangus, which is seen in 

 Echinocardimn cordatum in stronger expression ? If this " plaque de 

 soutien" corresponds to a myophore apophysis, it has more marked 

 analogies with the auriculee of Homognathous forms than with those of 

 Heterognathous forms. In any case, the question of atelostome 

 Echinoids requires further study. 



Ccelentera, 



Deep-sea Gorgonids.|l — W. Ktikenthal describes five new species of 

 Thouarella, a new species of Caligorgia, another of Stachyodes, and two 

 new species of PrinmoeUa. 



New Species of Alcyonium.lf — W. Kiikenthal describes Alcyonium 

 irw/u'ense sp. n. from the Mediterranean. It differs from A. palmatum 

 in colour (deep purple red with yellow polyps), size of polyps, armature 

 of polyps, shape of tentacles, number and form of pinnules, and in the 

 shapes of the coenenchyma spicules. The author notes that of the 

 reputed Mediterranean species, A. e%««s belongs to the genus Paralcy- 

 onium, and A. coralloides to Sympodium, sub-genus Erythropodium. 



* Zool. Anzeig., xxxi. (1907) pp. 229-30. 



t Op. cit., xsv., p. 670. X Tom. cit., pp. 749-50. 



§ Bull. Soc. Zool. France, xxxi. (1906) pp. 143-8 (5 figs.). 

 II Zool. Anzeig., xxxi. (1907) pp. 202-12. 

 t Jen. Zeitschr. f. Natur., xlii. (1906) pp. 61-72 (1 pi. and 12 figs.). 



