PLATE III 

 LATE EMBRYOS OF HETERODOHTUS JAPOKICUS 

 FiCT. 33. An einbr>'o with at least 88 myomeres (those near the tip of the tail are indistinct). 



Fig. 34. An embryo somewhat later than the preceding. The myomeres are not \^sible externally. 



Another embryo, in Dean's collection, slightly older than the one portrayed here, but younger than the one represented 

 in the following figure, measures 38 mm. (about one and one-half inchesl long. 



Fig. 35. An embrj'o later than the one shown in the preceding figure. Except at the tip of the tail, the 

 myomeres are not visible externally. 

 ^■\nother embryo in the same stage of development, found in Dean's collection, measures about 50 mm. (two inches) long. 



Fig. 36. An embryo, with myomeres visible only in the posterior half of the figure. The absence of ex' 

 ternal gill-filaments in this stage is unusual. 



Fig. 37. An embryo with profuse external gills. It measures about 70 mm. (tw.'o and three-fourths inches) 

 long. 



Fig. 38. This embryo is approximately 78 mm. (three inches) long. It has shorter and more delicate external 

 gills. 



Fig. 39. Note the lack of external giUs in this embryo, which is about 90 mm. (three and one-half inches) long. 



