415] COLORS OF TIGER BEETLES—SHELFORD 21 



the most complicated patterns are redncable to the usual plan or are 

 made up of unusual combinations of spots occurring in other groups of 

 species. Certain laws regarding direction of shifting of markings seem 

 to prevail. These will be noted again in another part of the paper, 

 (page 58). 



COLOR PATTERN AXD PIGMENT DEVELOPMENT 



As an example of the usual type of pigment development in Cicin- 

 dela let us follow the events in C. tranqueharica (PI. VIII). In the 

 yoiingest pupae there is essentially no pigment present except sufficient 

 in the eyes to give a slight brown color. This gradually becomes darker 

 until tlie end of about ten days when the eyes are a dull brown and the 

 process is apparently complete. At the end of 12 days the tarsal claws, 

 the tip of the mandibles, and the tips of the mandibular teeth have 

 received their full quota of pigment ; the pigment proceeds from the 

 tips proximally and by the 13th and 14th day pigmentation is com- 

 plete. On about the 13tli day the distal portion of the tibia of all of the 

 legs show pigmentation on the outer side and this proceeds to the more 

 pi'oximal portions most rapidly on the outside of the leg. The most 

 distal parts of the tibia are pigmented about 2 or 3 days later. Coin- 

 cident with the development in the tibia is the development in the 

 trochanters where it begins at the outer margin. A slight darkening 

 takes place in the mid-portion of the developing hind wing which is so 

 folded as to make the tip of the pupal wing show dark. At this time, 

 viz., at the end of from 14 to 16 days, the insect emerges. Often at or 

 before the time of emerging the first color centres of the dorsal side 

 of the abdomen have appeared on the last abdominal segment and more 

 rarely also the corresponding centers of the next to the last segment 

 are also present (Fig. 105, PI. VIII). Usually the animal en:erges 

 with the tibia, tarsal claws, part of the trochanters, eyes, mid-portion 

 of the hind wing, and tips of the mandibles pigmented (Figs. 101 and 

 105a). 



The later histon- exclusive of the elytra is as follows: Tlie pig- 

 mentation begins first on the distal joint of the antennae and the max- 

 illary palps (Fig. 101), and on the teeth of the maxillae. After about 

 8 hours the tip of the inner palp and the ligular portion of the labium 

 shows pigment (Fig. 102) ; next after about 12 liours the distal segment 

 of the labial palp and the outer wings of the labium darken (Fig. 103). 

 The gula begins to show pigment about as soon as the ligula, and the 

 pigmentation of this part is complete at the end of 12 to 15 hours. At 

 tlie time (after 12 to 15 hours. Figs. 103 and 107) the general pigmenta- 

 tioji begins to be most rapid, pigmentation begins to show strikingly 

 at the proximal portion of the appendages just noted and proceeds to 



