Explanation of the Plates illustrative of 33 



ZOEA. 



v^ Plate I. Fig^. 1, a, Zoea taurus magnified, after Slabber. 1, front spine, 

 2, 3 and 4, three oi its four pair of natatory members, s, dorsal spine, 

 s, 2, spine of the fourth abdominal segment. /, sub-abdominal fins. 



Fig. 1. b. The same animal after its metamorphosis according to Slabber. 

 1, a, interior antennae. 2, a, exterior antennae. 1, 2, 3, 4, its four members. 

 1'he want of the spines so remarkable in the former figure, and the changed 

 character of the tail are obvious. 



Fig. 3. Zoea pelagica magnified, after Bosc. a, 1, interior antennas. 

 a, 2, exterior antenna;, b, front spine, s, dorsal spine, e, eyes. /, natatory 

 members, t, tail. 



Fig. 2. Zoea observed by the author September 17th 1616, magnified. 1,2, 

 antennae. 3, 4, 5, 6, natatory members, s, dorsal spine, s 2, lateral 

 spines. Fig. 4, a, 4, b, Zoea observed by the anthor, August 22nd, 1816, 

 . magnified, a, 1, a, 2, antennae. /, natatory members. 



Fig. 5. Zoea clavata of Dr. Leach. 



Fig. 6, a, A Crustaceous animal observed by the author, September I9th 

 1816, S. Lat. 1/0 38', Long. VV. 27° 12', approximating the second form of 

 Zoea, magnified. 1, 2, 3, 4, natatory members. Fig. 6, b, its tail more 

 highly magnified. 



N. B. On the left hand side of Fig. 2, 4, and 6 the respective animals are 

 represented of their natural size and appearance. 



'^ Plate II. Fig. 1. Zoea observed by the author at Cove of its natural size. 

 Fig. 2. The same magnified, s, lateral spines, s 1, dorsal spine, s 2, 

 front spine, e, eyes. /, feet or natatory members, a, 1, inner antennae, a 2, 

 outer antennse. t, abdominal portion, with rudiments of the sub-abdominal 

 fins, t, 1, spinous forked tail — behind the corselet, the rudiments of the limbs 

 of the perfect animal or Crab begin to show themselves. 



Fig. 3. One of the mandibles magnified, a, toothed extremity, b, rudi- 

 ment of a palp. 



Fig. 4. Innermost maxilla magnified, a, lobed extremity, b, appendage. 

 s, ciliated scale. 



Fig. 5. Second maxilla magnified, a, b, r, its three divisions. 



Fig. 6. One of the a iterior pairs of members magnified, a, b, basil joints, 

 n, natatory or swimming division of 2 joints. /, inner division of 5 articuli. 



Fig. 7. One of the posterior pairs of members magnified, the same let- 

 ters denote the" corresponding parts in fig. 6, but in this the inner division has 

 but 2 articuli. 



Fig. 8. One of the outermost pair of antennre magnified, a, b, c, its 

 three divisons. 



Fig. 9. One the inner antennae magnified, a, b, its two terminSl lobes. 



Fig. 10. a, Labrum magnified, b, under Lip magnified. 



Fig. 11. Limbs of the future Crab disengaged from beneath the clypeus 

 on one side, magnified, a, chelate member. 1, 2, 3, 4, other members. 



Fig. 12. Member anterior to the claw, the rudiment of the outer pedi- 

 maxilla. 



