SCOLOPENDRA. 23 
since he supposed, although without grounds, that Say was referring to the posterior 
margin of the segments. 
In the British Museum, however, there is a North-American specimen, without 
special locality, which agrees closely with Say’s description; and since this form has 
never to my knowledge been figured, I take this opportunity of publishing a coloured 
drawing of it for comparison with the specimen of S. viridis from San Andres in 
Mexico (Tab. II. fig. 27). The difference between the two is startling enough; but I 
presume, from the confidence with which S. viridis of Say has been discussed by those 
who have written upon the North-American species of Scolopendra, that this peculiar 
pattern of colouring is inconstant. Wood seems to have been well acquainted with 
specimens presenting it. | 
I may add that in Abbot’s drawings of Georgian Aptera, vol. xv., there is a figure of 
a centipede agreeing almost exactly with Say’s description of S. viridis. It has the 
antenne deep greenish blue; the head and first segment deep olive-green, the rest of 
the segments with a green longitudinal median band and yellow sides ; the anal legs 
olivaceous, the rest of the legs from the patella to the claw also deep green, but the 
femur yellow like the maxillipedes. Abbot only appears to have seen one specimen, 
that was taken under a log in April. He says it is a rare species, the smaller members 
of the genus [? 8. parva, of Wood] being oftenest met with. 
The Mexican examples before me that I here refer to S. viridis have been received 
from the following localities :—Ciudad (Forrer) (one specimen, 59 millim. long); San 
Andres Tuxtla (two specimens, identified by de Saussure as 8. tolteca) ; Omilteme (one 
example, 87 millim. long, anal leg 15 millim. long, with stout segments; brownish 
green in colour, with the hinder borders of the terga deeper green). Examples were 
obtained by Dr. Stoll in Guatemala at the following localities: Volcan de Pacaya (three 
specimens, 74, 52, and 42 millim. long); San Miguel Uspantan (one specimen, 43 
millim.); Antigua (one specimen, 55 millim.); Guatemala city (four specimens, 75, 
59, 47, and 45 millim.); and Quezaltenango (one specimen, 37 millim.). 
The single specimen from Costa Rica measures 55 millim. 
12. Scolopendra pachygnatha, sp. n. (Tab. II. figg. 3, 3 a, 5.) 
Colour of trunk and legs uniform olive-green ; anterior end of body, with antennz, and posterior end of 
body ferruginous. 
Head suborbicular, rather small, very weakly punctulate, not suleate. Antenne composed of 25 segments, 
whereof the basal 6 are naked. Mawillipedes with their coxal plate densely punctured and striate 
anteriorly, deeply suleate behind; dental plates prominent, longish, diverging, quadridentate; fentoral 
segments also basally coriaceous. 
Terga smooth, scarcely punctured, from the second to the twentieth bisulcate, from the seventeenth to the 
twentieth marginate ; sterna smooth, conspicuously bisulcate. 
Anal somite small: tergite not sulcate ; pleura densely punctulate, the process almost absent, very short, blunt, 
and tipped with many spinules; sternite narrow ; legs longish and slender, the width of the segments less 
than half their length, angular process on the femur scarcely apparent, tipped with 1 or 2 spines; femur 
