242 BULLETIN OF THE UNITED STATES FISH COMMISSION. 



Plate 26. 



Fig. 39. Young, immature lobster; male. Length 47 mm. Drawn and colored from nature July 18, 

 1891. This animal was injured and brought up by accident in a lobster pot in Woods 

 Hole Harbor. (No. 22, table 33.) Enlarged 2f times. 



Plate 27. 



[The stage or molt to which each drawing belongs is shown by roman numerals on plates 27 to 35.] 



Fig. 40. Right first antenna of first larva, from below. The inner branch or flagellum of this append- 

 age is now present as a very small unsegmented rudiment, which grows out of the pri- 

 mary stalk from its under side toward the middle line. 36 times natural size. 



Fig. 41. Left first antenna of second larva, from below. Segmentation of flagellum of exopodite not 

 yet visible, or but faintly marked; endopodite tipped with one long and one or two short 

 seta?; shows slight traces of segmentation. Nine bunches of olfactory seta? present, 4 to 

 6 in a bunch, distributed in two longitudinal rows. 36 times natural size. 



Fig. 42. Left first antenna of third larva, from below. Segmentation of flageila more marked. Outer 

 and inner branches separated by pressure. 36 times natural size. 



Fig. 43. Left first antenna of fourth larva, from above. Masses of brown pigment are seen in the 

 auditory chamber. Segmentation of parts very distinct, au, auditory organ. 36 times 

 natural size. 



Fig. 44. Left first antenna of fifth stage, from below. Lobster No. 3, table 34. Parts shown in 

 natural position. 36 times natural size. 



Fig. 45. Right first and second antenna? of first larva, from above. Inner edge of exopodite of first 

 antenna bears a fringe of 22 to 23 plumose seta?. 36 times natural size. 



Fig. 46. Right second antenna of second larva, from above. 36 times natural size. 



Fig. 47. Left second antenna of third larva, from above. 36 times natural size. 



Fig. 48. Left second antenna of fourth larva, from below. Flagellum divided into 40 segments. 36 

 times natural size. 



Fig. 49. Proximal portion of left first and second antenna? of lobster in fifth stage, seen from below. 

 Lobster No. 28, table 34. Drawn without pressure, gr, papilla on which green gland 

 opens. 36 times natural size. 



Plate 28. 



Fig. 50. Left first and second antenna? of fifth larva, as seen from above. From lobster No. 28, table 34. 



36 times natural size. 

 Fig. 51. Right first maxilla of first larva, from anterior face. 153 times natural size. 

 Fig. 52. Terminal joint of left fifth pereiopod of first larva from anterior side. 50 times natural size. 

 Fig. 53. Tip of endopodite of first maxilla of first larva. 45 times natural size. 

 Fig. 54. Front view of mouth and surrounding parts — labrum, metastoma, and mandibles — of first 



larva. Dark-red chrornatophores occur on the mandibles and labrum. The mandibular 



palp sometimes carries two seta? at its tip. 154 times natural size. 

 Fig. 55. Right mandible of fourth larva, from behind, showing groove and cutting edge. 36 times 



natural size. 

 Fig. 56. Left mandible of fourth larva, from outer side. Hard, chitinous part next to cutting edges, 



bluish steel color. 50 times natural size. 

 Fig. 57. Mandibles of fifth larva, from anterior side. Drawn from the molted shell of lobster No. 



23, table. 34, August 10, 1892. Length of larva before molt 13 mm. 36 times natural 



size. 



Plate 29. 



Fig. 58. Left first maxilliped of first larva, from the inner side. 125 times natural size. 



Fig. 59. Left first maxilliped of fourth larva, from outer side, showing tegumental glands in second 



segment (basis). 52 times natural size. 

 Fig. 60. Right second maxilla of first larva, from outer side. 153 times natural size. 

 Fig. 61. Right first maxilla of fourth larva, from inner side. 52 times natural size. 

 Fig. 62. Right first maxilla of fifth larva, from outer side, showing tegumental glands in second 



segment (basis). Drawn without pressure. From lobster No. 27, table 34. 50 times 



natural size. 



