324 /S. I. Smith — Early f>taf/es of Hippa talpoida. 



sub-median spines, two eacli side between these and the next outside 

 of them, from three to twelve in each intersjiace between the other 

 spines, and from thirty to foi'ty between the outer spine each side 

 and the tooth of the Lateral margin. 



The zoese in this stage were frequently taken at the surface, both 

 in the day-time and evening, from August 7th to September 10th. 

 In life, the entire animal is translucent with a slight greenish tint, 

 except a brilliant spot of orange pigment with metallic lustre at the 

 base of the rostrum and at the base of each of the lateral spines. 

 These bright spots Avould often catch the eye in looking into the 

 water when the rest of the animal was nearly or quite invisible. 

 Their motions in the water are similar to those of zoeae in general, 

 except that the movements are much less rapid, and they seem com- 

 paratively sluggish in habit. In aquaria they were usually seen 

 swimming slowly about the surface, seldom whirling oif with the mad, 

 gyratory motion so characteristic of many Brachyuran zoete. 



Individuals in this last zoea-stage, when kept in confinement, often 

 changed, at a single molt, to the megalops-stage described beyond, 

 although many died during the process of molting. 



The following table shows the relative measurements of specimens 

 in each of the zoea-stages described : 



Second Third Last 

 Stage. Stage. Stage. 



Length from tip of rostrum to posterior margin of carapax, . . 3-2mm. 4-4mm. 6-2™™- 



Breadth between tips of lateral spines, . 2-2 2-8 4-3 



Length of rostrum from tip to front of ocular peduncles, 1-8 2-8 4-7 



•' " lateral spines, about, '8 I'l 1"3 



" " carapax from front of ocular peduncles to posterior 



margin, -- 1'3 18 2'5 • 



Breadth of carapax in the middle, "9 12 r7 



'< " telson, - -. -7 1-0 1-4 



Megalops-stage. 



In specimens recently changed from the last zoea-stage, the length 

 of the carapax is slightly over 3"'"' and that of the abdomen, when 

 fully extended, a little less, while the breadth of the carapax is about 

 2mm j^ general form, the young in this stage resemble the adult, 

 but diffei- essentially in much the same way that the Brachyuran 

 megalops diflTers from its adult ; the eyes still being relatively large, 

 with short and thick peduncles, as in the last stage of the zoea, while 

 the second, third, fourth, and fifth abdominal segments, as well as the 

 sixth, are provided with strong swimming appendages. 



