266 EXPEDITION TO JAPAN. 



lower than the branched portion, and increasing gradually in height from the first spine, which 

 is half the length of the last. Anal fin with the short spines increasing in length from the first 

 to the third, the soft rays longer than the spines, and divided into two portions, the first shorter 

 than the last. Caudal broad at the base, and rather deeply emarginate. Pectorals and ven- 

 trals of medium size, and with no particular characters. Anal opening halfway from first anal 

 spine to the membrane attaching the ventrals to the body. Behind it a peculiar orifice, before 

 mentioned. B. 6? D. 10, 22; A. 3, 27 ; P. 19 ; V. 1, 5 ; C. 19." 



" When fresh, of a dirty pale bluish; lighter on sides, and white beneath. Lips pale flesh 

 color. Pectoral of a bright light brown hue. Spinous dorsal of a brownish grey, with dirty 

 yellow along the base, and with a rather broad blackish border. Soft dorsal and anal fins of a 

 dirty greyish brown. Caudal blackish. Ventrals blackish green, yellowish at base of soft rays. 

 Irides silvery white." 



" This species does not exceed eight or nine inches in length. The Japanese name is Tanago. 

 Caught in the spring in great numbers in the Bay of Nagasaki, and eaten daily at that time." 



The figure by the artists of the United States Japan Expedition is identical with the one in 

 the Fauna Japonica, though rather darker in coloring. It does not show the specific characters 

 distinctly. 



Bleecker, in a paper published in the 25th part of the Transactions of the Batavian Academy 

 of Arts and Sciences, entitled Nalezingen op de Ichthyologie van Japan, characterizes the genus 

 Ditrema as follows : 



" Dentes maxillis minimi pluriseriati antice tantum aliquot conici majores; dentes vomerini 

 vel palatini nulli ; rostrum in tubum subhorizontalem protractile ; ossa opercularia et suborbi- 

 talia edentula ; pinna dorsalis unica ; aperturae analis et genitalis distantes ; pinna analis 

 spinis 3, radiis numerosis subsimplicibus ; membrana branchiostega radiis 6." He gives the 

 species the name Temminckii. 



He examined one specimen only, and places it between Caesio and Gerres. 



Neither Schlegel nor Bleecker had suspected that this fish belonged to the interesting family 

 of viviparous fish recently discovered on the opposite shores of the Pacific in California. 



Upon showing the published figure of the Ditrema, and the figure of it by the American 

 artist, to Diengkitsch, he immediately described its viviparous faculty, and added that it has a 

 way of escaping from the fishermen's nets by keeping close to the sides of a rock or bank. He 

 confirmed the name Tanango given to it in the Fauna Japonica, which is the name of a peculiar 

 net, perhaps used for catching it. In the Notices et Extraits des Manuscrits, Tom. XL, 

 parti., 1827, there is a notice of Japanese encyclopedias, by Mons. Abel Eemusat, a highly 

 interesting paper, in which a Japanese fount of letters is used for the first time. In the list 

 offish, page 216, No. 37, is one called in Chinese Ju or Lian, in Japanese Tanako, " a fish 

 which swims in pairs ;" and in a foot-note Mons. A. K. says : " It is asserted that this fish is 

 viviparous, and the same in the case with the species called Anagaiwo, Ei, Same, Heka or Fuha, 

 and Sakataiwo." These five names seem to designate particular species of eels or lampreys, 

 plaice, dog-fish, (acanthias ?) cat-fish, (silurus,) and for the last, apparently, a bream, or per- 

 haps another variety of Ditrema. This very interesting note, the authority for which is not 

 given, induced me to compare the Ditrema with a specimen of the California viviparous fish 

 procured by Dr. John L. Leconte in that country in 1851, and with the descriptions of the 

 Embiotocoidae and Holconoti, by Agassiz, Gibbons and Girard, in the Am. Journal of Sc. and 

 Arts, in the Proc. of the Acad, of Nat. Sc. of Philadelphia and of the Boston Soc. of Nat. Hist., 



