49. Os. has been selected as the holotype, while the paratypes are 

 represented by Nos. 124. Os., 128 Os., 157. Os. (the largest individual), 

 232. Os. (the smallest individual) and 260. Os. Dimensions of these in- 

 dividuals specifies Table 3. 



Description. The species here considered represent small-sized 

 fishes — the length of the largest specimen is 33.4 mm without the 

 caudal fin. The body is laterally compressed with the greatest depth 

 immediately behind the head, and narrowing up gradually without 

 abrupt curves in the ventral profile, so characteristic of the genus Argy- 

 ' ropelecus Cocco or Sternoptyx Harm. The greatest depth of body fits, 

 2.3 to 3.6 times in to the body length without the caudal fin; i.e. the 

 depth of body represents 27 — 43 percent of the body length without 

 the caudal fin. Hence some specimens seem short and deep others 

 considerably more slender and longer. Plate H presents the deepest 

 individuals of this species, Plate III, Fig. 1 shows the most slender. 

 There is no distinct predominance of the "deeper" forms over the "more 

 slender" or vice versa. If some, arbitrarily selected, groups be dif- 

 ferentiated among the variability range given above, the respective 

 numbers of individuals (as based on the 26 complete specimens) are as 

 follows: 



Group 



I 



II 

 III 

 IV 



Number of individuals 



Relation of maximum body 

 depth to length without 

 caudal fin (percent) 

 27—30 

 30—35 

 35—40 

 40—43 



Skull. In 21 individuals the length of skull represents 32 — 36 percent 

 of the body length without the caudal fin, in one individual 28 percent, 

 in two 30 percent, in one 38 percent and in another 39.9 percent. 



In the neurocranium, in addition to the parasphenoid (Fig. 5) fairly 

 broad frontalia can also be seen. The inadequate state of preservation 

 of the other bones does not permit the particular elements to be 

 distinguished. 



A long, pasteriorly, gently arcuate maxillare, with a narrow, 

 likewise arched supramaxillare, is to be observed in the cranium vis- 

 cerale of many individuals. The anterior part of the mouth opening is 

 rimmed by the narrow, elongated premaxillare. In numerous specimens, 

 the presence has been noted of minute, conical denticles along the 

 whole length of the lower margin of the premaxillare, as well as in 



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