110 KEPORT — 1873. 



The author, however, could not see sufficient grounds for the removal of Mertens's 

 genus from the true Hi/clroida, with which the Medusa now described agrees in all 

 essential points, including the form and disposition of the gastrovascular and 

 generative systems and the structure of the marginal lithocysts. Neither could he 

 aoree with Alexander Agassiz in identifying it with Trachi/iwma. The greatly 

 developed solid peduncle by which the manubrium in Circe is suspended frorn^ the 

 summit of the umbrella-cavity (in a way, however, which has its parallel in Tinia 

 among others), is of itself a character of generic importance by which Circe must be 

 kept apart from Trachynema. It is true that Gegenbaur's TracJti/nema has the 

 character of a young form ; and until we have further evidence of its adult state its 

 affinities cannot be regarded as established. 



Ge"-enbaur believes that he has established the direct development of Trachy- 

 wem«°from the egg without the intervention of a hydriform trophosome ; but 

 unfortunately we have no data by which to compare in this respect Circe with 

 Trachynema. 



It must be admitted, too, that in the imperfect contractility of the marginal ten- 

 tacles and in the somewhat greater firmness of the umbrella- walls the little medusa 

 described in the present communication possesses characters which look towards the 

 yEyinicke ; but these are by no means sufficiently strong to j ustify its separation from 

 the ordinary hydroid Medusae. 



5. Tomopteris. 



A few young specimens of this beautiful little worm were obtained ; and the 

 author was enabled to confirm the statements of Grube and of Keferstein, who 

 describe in it a double ventral nerve-chord, though other observers have failed to 

 discover this part of the nervous system, and throw doubt upon its existence. In 

 adult specimens examined some years previously by the author no ventral chord 

 could be detected. 



The ventral portion of the nervous system consists of two flat ribbon-shaped 

 chords, which are given oft' from the inferior side of the nerve-ring which sm-roimds 

 the pharynx just behind the mouth. These run parallel to one another, separated 

 by a narrow interval ; they lie on the ventral walls of the animal, and may be 

 traced through the narrow tail-like termination of the body as far as its extremity. 

 They present no ganglionic swellings ; but opposite to every pair of feet each sends 

 ofl" a filament which passes to the foot of its own side, in which it is distributed. 



Dr. Anton Dohm has just informed the author that he, too, has distinctly seen 

 the ventral chord of Tomopteris. 



On the Distribution of the Antelopes in Southern and Western Asia. 

 By W. T. Klanfokd. 



On the Fauna of Persia. By W. T. Blanford, F.G.S., C.M.Z.S. 



Persia being situated on the limit of the region occupied by the Palsearctic fauna, 

 presents in dilferent parts of the country several peculiarities, in consequence of 

 types belonging to the Indian and desert faunse being largely intermixed with each 

 other, and with those peculiar to the Palsearctic province. 



In the extreme north the animals are identical with those of the neighbouring 

 parts of Europe and Asia, the steppe fauna of Southern Russia being met with in 

 the open parts of the country ; whilst the dense forests of the shores of the Caspian 

 are chiefly inhabited by the same animals as occur in the woods of South-eastern 

 Europe and Asia Slinor, mixed, however, with a few Asiatic types, as the tiger, the 

 common pheasant, and a crotaline snake (Halys). Throughout the greater portion 

 of the Persian territory the fauna is of the desert type, marked by the prevalence of 

 such forms as Eqmis hemiunus, Gazella, Gerbillus, tlnfeo ferox, Gyps ftilvus, Buca- 

 netes yithayineus, Pterocles, and Houhara, Eremias, Psammophis, Eryx, &c. ; whilst in 

 the south the purely Palfearctic forms either disappear entirely, or are represented by 

 winter migra,nt3 only, and several Indian fonns make their appearance, e. g. Gazella 



