300 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Myology of Chondropterygian Pishes.* — J. Chaine calls attention 

 to a muscular layer on the ventral surface of the cephalic and branchial 

 regions, which is remarkable for its many points of insertion in different 

 parts of the skeleton, and for its different arrangements in the various 

 species. He homologises it with the " transverse jugular " of the other 

 vertebrate Classes. 



Sub-Orders and Families of Teleostean Fishes.f — G. A. Boulenger 

 gives a very welcome synopsis of these groups, in which his aim has been 

 to build on phylogenetic lines. The most important character dis- 

 tinguishing the Teleostei from the Holostean Ganoids appears to be the 

 presence of an ossified supraoccipital bone. Remnants of primitive 

 characters, such as Ganoid scales, fulcra, rudiments of a splenial bone, 

 spiral valve to the intestine, multivalvular bulbus arteriosus, are still 

 found in some lower Teleosteans, but no longer in that combination which 

 characterises the preceding order. Although Albula is exceptional 

 among all Teleosteans in having two transverse series of valves to the 

 bulbus arteriosus instead of one, no Ganoid has fewer than three. The 

 order Teleostei, thus defined, is divided into thirteen sub-orders, whose 

 characters are fully indicated. Brief definitions of the several families 

 are given under their respective sub-orders. 



Glands of the Mouth-Cavity of Petromyzon.J— W. Haack describes 

 the musculature, development, and histological structure of these glands. 

 They are a pair of minute multicellular glands, about 3 mm. long and 

 0*5 mm. in diameter, having the form of an oval sac, constricted in its 

 hinder third in a dumb-bell like form. They are imbedded in the 

 ventral surface of the basilaris muscle. There is a long slender efferent 

 duct opening in the mouth-cavity. The gland shows a structure quite 

 different from a salivary gland, its secretion has a weakly acid reaction, 

 and no diastatic ferment can be found in its contents. 



Japanese Myxinoids.§ — Bashford Dean describes Homea ( = Bdello- 

 stoma) burger i, H. olcinoseana sp. n., the largest known Myxinoid, and 

 Paramyxine atami g. et sp. n. He throws doubt on the conclusion of 

 Nansen and Cunningham, that Myxine exhibits protandric hermaphro- 

 ditism. It is necessary to collect large numbers throughout the year 

 to reach a well-established conclusion on this point. 



Japan seems to be the most favourable region for the study of 

 Myxinoids. " In an especially conservative locality, as at Misaki, we can 

 still catch a glimpse, so to speak, of the better days of the Myxinoids, for 

 here there are living side by side three distinct genera represented by at 

 feast four species." The author directs attention to the wide range in 

 the variational characters of species. 



Thames Fisheries.! — James Murie reports on the physical forma- 

 tion, fauna, and fisheries of the Thames estuary, incorporating a wealth 



* Proa-Verb. Soc. Sci. Bordeaux, 1902, pp. 18-19. 

 f Ann. Nat. Hist., xiii.(1904) pp. 161-90. 

 % Zeitsch. wiss. Zool., lxxv. (1903), pp. 112-46 (2 pis.). 

 § Journ. Coll. Sci. Univ. Tokyo, xix. (1904) art. 2, pp. 1-23 (1 pi. and 4 figs.). 

 || Report on Sea Fisheries and Fishing Industries of the Thames Estuary. Kent 

 and Essex Sea Fisheries Committee, 1903. See Ann. Nat. Hist., 1904, pp. 325-6. 



