S.\M)-I,ALXCK. 



>75 



Ammodijtcs hmvcd. Cuv., lit'yuc Anim., cd. 2, lom. II, p. lUiO: 

 NlLss., Prodi: Iclit/ii/ol. Scind., p. G3; Kn., 1. c, p. 593: 

 NiLss., Skand. Fn., Fisk., p. 65G; Mai.mok., 1. c; LiNnsTit.. 

 GoU. L. Hush. SSllsU. ArslxT. ISfiG, p. 24 (sep.); Mki.a, 

 Vcrl. Feiiii., p. 20t;, liil.. IX; I.ii.u., 1. t-., p. 221. 



Tlic Saiid-IjauiK'C never attains so great a size as the 

 niaxiinuui size of the Sand-Eel. Kkover's largest spe- 

 I'inu'U wa.s 1^7 iiini. long; a s|iecinu'ii tVoui Cireonland, 

 l)r()Uglit liDHu' li\' ( >. ToiJici.i,, nicasures 204 ninu fVom 

 the ti|> of the lower jaw to the end of the longest ra}-s 

 of the eandal hn, or I'.IT nnu. from the tip of the snout 

 to the end of tiie miildle ra\s of the same tin. 



The l)odA" is generalh' soniewliat deeper and more 

 eompressed than that of the Sand-Eel, though no constant 

 eharacter ean he drawn from tins relation. The greatest 

 depth of the body, aeross tlu' l)i'lly, varies in ordiiiar\' 

 cases between aliout !l and 10' . % of the lengtii from 

 the ti]i of tiie lower jaw to the end of the outer ravs 

 of the caudal iin, and the greatest lireadth between 

 about 66 and 7.t % of the greatest depth. We have 

 found tiie dejith at tlie lieginning of the anal tin to vary 

 lietween 6',-, and '.l' - %" of the length of the body 

 from the tip of the snout to the end of the middle 

 caudal rays; and, in the .same specimens, the greatest 

 breadth varied between 4 and 7' , %'' of the same length. 



In speeimeiis of equal size tiie head is of essen- 

 tially the same shape as in the Sand-Eel; but as a rule 

 it is shorter. In specimens between 1)5 and 197 mm. 

 long we have found its length to \ar3- between 19 and 

 17'' 4 % of that of the body. The longitudinal diameter 

 of the eye varied in tliese specimens between 20 and 

 13 /» of the length of the head. The length of the 

 snout varied between 64 and 56 % of the postorbital 

 length of the head or between 33 and 30 % of tlie total 

 length thereof. The least breadth of the interorbital 

 space varied between 2' ., and 3",,. % of tlie length of 

 the body or between 12^ .-, and 19 'A, % of the length 

 of the head. 



In the nostrils we tind scarcely any difference from 

 those of the Sand-Eel; l)ut the structure of the month, 

 as we have remarked above, affords one of the most 

 important characters for the Sand-Launce and the forms 

 akin to it in this res])ect. The mobility of the inter- 

 maxillary Ijoiies is ]>roduced in the same manner as in 

 the case of most other tishes, and in striking contrast 

 to the Sand-Eel. The difference lies partly in the long 



nasal processes, wiiieii gli(h' forward and backward in a 

 groove in the upper surface of the ethmoid lione, partly 

 in the greater length of the musculai- band tiiat extends 

 under each of these processes, starting from the inner 

 (posterior) surface of the front of the intermaxillary 

 bone and from its articular process (cf. the explaiiatitJii 

 of tig. US, p. 463, above), and attaeiied to tlii' inward 

 vomeral process of the maxillary bone, which |)rocess is 

 closely united by ligaments to the anterior end of the 

 vomer. These two muscular Ijands serve to draw back 

 the intermaxillary bones. The protrusion of the inter- 

 maxillary bones is effected by their union to tlu^ lower 

 jaw- by skin, muscles, and ligaments, and they thus 

 follow the lower jaw when it is depressed. The anterior 

 end of the maxillary l)ones is rendered independent of 

 this downward motion ])y tiie union of tiie vomeral 

 processes to the vomer; and on casual examination these 

 processes, with their sharp, transverse, osseous points, 

 present a, confusing resemblance to the teeth on the 

 head of the vomer in the Sand-Eel — they iiave several 

 times been confounded \vitii those teeth. Tiie length of 

 the upper jaw shows even relative increase with age 

 from the earliest stages until the fish is of middle size, 

 but it subsequently seems to be retrogressive, unless 

 our observations are based on individual variations. In 

 a specimen 30 mm. long we find tins length to be 22";., 

 ?4 of that of the head, and in larger specimens, up to 

 a lengtii of aI)out 13 cm., this percentage increases to 

 about 33; but in our largest specimen the proportion 

 is no more than 28', 2 ?*• Tlit; lower jaw is usiialh- 

 shorter than in the Sand-Eel, its length being about 

 8 % (between 8'6 — exceptionally 9"3 — and 7'6 %) of 

 that of the body, or about 45 % (between 47"8 — in our 

 smallest specimen 49 — and 42"8 ?o) of the length of 

 the head, and never so much as 15 % (14'2' — •12'2 %) 

 of the length of the base of the dorsal fin. The conical 

 tip in which the lower jaw projects bevond the tij) of 

 the snout, is also generally less than in the Sand-Eel, 

 and seems at most not to exceed Vi of tlie length of the 

 snout proper. The gill-rakers are setiform in this species 

 too, and number 22 or 23 on tiie first braneliial arch. 

 The lips, tongue, palatal folds, pliaryngeal bones, and 

 gill-covers resemble those of tlie Sand-l-]el, l)ut the oper- 

 culum is more scalene, with the lower side (along tlie 

 suboperculum) perceptibly greater than the upper. The 



" In the S.ind-Ecl between 0- j and 8 



from lG-3 \ to 15-3 



Scnnrlinaviari Finht;. 



