793 



Tlic Icnytli of tlie liead varies bc'twccn 11) iind 21 

 % of that of tlic ]HK\y, its size beirio' thus soinewliat 

 below the average among the Scandinavian Cj'prinoids. 

 It is rather pointed, of uniform thickness, and com- 

 pressed, at the to]) convex, witii fairly parallel cheeks. 

 The facial line is straigiit from tiie occiput to tlie tip 

 of (lie snout. The breadth of tiie interorbital space 

 measures about ^,\^ of the head, and is generally some- 

 what greater than the longitudinal diameter of the eyes, 

 but sometimes e(|ual to this diameter, wiiich also differs 

 onh' sliglith- from tlie length of the snout. Tlie nostrils 

 he on a le\el ^\■itil the upjier margin of the eyes, 

 nearer to tiie ej'es than to the tip of the snout; and 

 the distance between the anterior nostrils is ecjual to 

 that between either of them and the middle of the tip 

 of the snout. As usual in this family, the two nosti-ils 

 of eacli side are sejjarated by a nari'OAv dermal ridge, 

 raised in a lobate form, and the shape of the nostrils 

 varies with the position of this ridge: when it is thrown 

 back, the anterior is round, the posterior crescent- 

 shaped. The situation of the eyes is such that the 

 postorbital length of the head is as a rule somewhat 

 less, but sometimes rather more, than half (44 — 52 '-h) 

 of its entire length. The mouth is turned sharply up- 

 wards, its entire cleft lying in front of tiie perpendi- 

 cular from the nostrils, which line, when the mouth 

 is closed, touches the hind extremity of the maxillary 

 bones. A small notch in the sharp tip of the snout, 

 which is formed by the intermaxillaries (the margin 

 of the upper lip), receives the blunt and rather pro- 

 minent point of the lower jaw. The length of the 

 upper ja^v from the middle of the tip of the snout is 

 often almost equal to the length of the snout, measur- 

 ing 29—26 % of that of the head. The length of the 

 lower jaw is 35 — 40 % of that of the head. The gill- 

 openings are fairly large, the branchiostegal membranes 

 coalescing with the isthmus almost beside each other, 

 a little in front of the perpendicular from the hind 

 margin of the preoperculum. The gill-rakers are close- 

 set: in the outer ro^v on the front of the branchial 

 arch (16 or 17 in number) they are slender and waud- 



siia|ied, wiiile in the inner row on this arch and in 

 both rows on the other arclies and on the outer an- 

 terior margin of the pharyngeals they are short and 

 of a [)ointed triangular form. The pseudobranchia^ are 

 \\v\\ developed. Tiie piiaryngeal teeth are distinguished, 

 liere ;ls in tlie liudd, by the pectination of the masti- 

 Ciitory surface, at least before it is worn smooth, in 

 the case of the three or four posterior teeth in the 

 inner row. Tiie two anterior teeth or at least the first 

 tooth in this row, are as usual more conical, the se- 

 cond witli or witiioiit pectinated ma.sticatory surface, 

 or with this surl'act' worn smooth. Such is also the 

 form of the two small teeth in- the outer row. Tiie 

 jiharyngeal cartilage is oval, with grooves obliquely 

 crossing the masticatory surface, as in the majority of 

 the Leuciscines described above, and with the hind 

 (lower) extremity somewhat raised, a trace of the in- 

 verted canaliculate form more highly developed in the 

 larger Leuciscines. 



The dorsal fin begins at about the middle of the 

 length of the body" or a little further back. It is of 

 almost the same trapezoidal form as in the Leuciscines, 

 with the length of the last ray at least rather more 

 tlian '/3 of that of the longest ray, wdiich here seems 

 hardly to exceed 15 %'' of the length of the body. 

 The base of the dorsal fin measures about Vn" of the 

 length of the body. The anal fin begins below the 

 posterior part of the dorsal''. It is long', low behind, 

 and forms a slight arch at the concave inferior mar- 

 gin. The first ray is hardly perceptible, the second 

 half as long as the third, the fourth the longest^ and, 

 like the following rays, bi'anched at the tip. The 

 caudal fin is deeply forked, the lower lobe being some- 

 what longer than the upper, and measuring somewhat 

 more than V5 of ^he length of the body. 



The pectoral fins are obliquelj' and bluntly pointed. 

 Tlieir length is about ' ,, (16'/,,— 17' , %) of that of 

 the body. The ventral fins are inucli shorter, measur- 

 ing about 12 — 13 % of the length of the body. Their 

 position is such that the distance from the tip of the 

 snout to their insertion' does not seem to exceed 



" .\t a distance from tlie tip of flie snout measuring 50 — 52' ., of the lengtli of llie liody; tlie Litter percentage in our oldest fe- 

 male specimens. 



' Varying, according to our measurements, between 13' , and 14'' j %. 



' According to our measurements 87 — 9'7 %. 



'' At a distance from the tip of the snout measuring about 59 % (57'4 — 59'3 %) of the length of the body. 



' The base of the anal fin measures about 17 % (16"4 — 17G %) of the length of the body. 



-'' About 11 »i (11-8 — 10-5 %) of the length of the body. 



!' 40 — 43 ?, of the length of the body. 



