﻿Dec. 1895.] Dyar and Morton. New York Slug Caterpillars. 149 



series of species with reduced tubercles and in the lowest of the spined 

 Eucleids {Phobetron, fig. 12); but in the higher spined forms, the 

 middle row disappears, precisely as it has disappeared on joint 4 of 

 Megalopyge, probably in response to a similar need. In all the spined 

 Eucleids, there is also a reduction in the number of warts on the first 

 abdominal segment, which will be specially described under Sibine 

 stimiilea. 



Along the three abdominal rows of tubercles, and correspondingly 

 on the thorax, the body is more or less ridged. We shall call these the 

 subdorsal, lateral and subventral ridges respectively. Owing to them 

 a section of the body of a Eucleid larva forms a hexagon instead of a 

 •circle, as in most other Lepidoptera. This may be regarded as the 

 fundamental type (fig. 13), though it nowhere actually exists that we 

 know of. Usually the space between the lateral and subventral ridges 

 is contracted, giving the form shown in fig. 14. In Sisyrosea the upper- 

 most space is also contracted, giving the form of fig. 15, the flattest 

 Eucleid larva known to us. In Eulimacodes, a quite different process 

 has taken place. Instead of the lower side-area being contracted, the 

 upper side-area is reduced nearly to obliteration, and we get the outline 

 of fig. 16, a square. 



The surface of the body is divided by these ridges into three areas. 

 We shall name them as follows : 



The unpaired dorsal space between the two subdorsal ridges we 

 ■shall call the dorsal space. The space on each side between the sub- 

 dorsal and lateral ridges, the lateral space. The space between the lat- 

 eral ridge and the lower edge of the body, which contains the spiracles, 

 the subventral space. 



The surface of the skin is not smooth in the later larval stages, but 

 is sunken in certain more or less well defined areas. These areas have 

 a flat bottom and more or less perpendicular sides and appear to be 

 possible in these larvae on account of the unusually thick skin. They 

 have the following definite arrangement, though they may be imper- 

 fectly developed or even partly absent, as we shall describe in indi- 

 vidual species : In dorsal space (i) a median row of large depres- 

 sions, intersegmental, we shall call the dorsal row ; (2) a paired row 

 just above the subdorsal ridge; segmental, and therefore alternating 

 with the dorsal, we call the addorsal depressions. In the lateral space 

 (3) a segmental row of small depressions just under the subdorsal ridge, 

 the upper lateral segmental, (4) a large intersegmental row in the 

 middle of the lateral space, the lateral depressions, two rows closely 



