8 BULLETIN OF THE LIVERPOOL MUSEUMS. 
1-4; aculeus of vesicle strongly hooked in its distal half, vesicular tooth 
smaller, closer to the base of aculeus. Pectinal teeth 8. (Total length of ? 
49 mm.) 
(2) Heteronebo forbesii. 
b. Hand convex above with very weak median and finger keel ; ocular 
tubercle larger, distinctly though not deeply sulcate ; inferior median crests 
distinct on caudal segments 1 and 2; aculeus of vesicle only lightly curved, 
vesicular tooth larger and much more remote from the base of the aculeus. 
Pectinal teeth 8-9. (Total length of 9 42 mm.) 
(3) Hemiscorpius socotranus. 
? Colour.—Olive brown above ; chele ferruginous with crests and digits 
infuscate ; legs olive yellow. 
Carapace and tergal plates densely punctured ; very finely and closely 
granular laterally and in the median depression; core and _ sterna finely 
punctured. Til about four times as long as the carapace ; superior and 
inferior lateral keels strong and granular on all the segments ; median lateral 
keel absent on Ist and all the following segments except the 5th, where it 
is posteriorly abbreviated ; inferior lateral keels distinct on all segments, 
but weakly granular on the anterior; inferior median keel absent on segment 
1, present in the posterior half of segment 2, developed on segments 3-5; 
intercarinal spaces finely granular; vesicle finely and coarsely punctured, 
finely granular. Chelw very finely and closely punctured ; hand nearly flat 
above with smooth external finger keel and median longitudinal keel. Legs 
punctured and finely granular. (Genital operculum broadly cordate, without 
median suture, except in front. Pectinal teeth 10. 
é Differing from ¢? in its more slender build, longer tail, and much 
more strongly granular upper surface of body and chele. Carapace as long 
as first and } the 2nd caudal segment. Jwil about 5 times as long as 
carapace, its 5th segment much longer than carapace ; vesicle more elongate 
than in 2. Pectinal teeth 12-13. 
Measurements in millimetres.— ? Total length 38, length of tail 
19:5, of carapace 5, 5th segment of tail 4:5. 3 Total length 38, length of tail 
22, of carapace 4:2, 5th segment of tail 5-2. 
Locality.—Sokotra (Hadibu Plain, Jena-agahan, 1200-2500 feet ; Adho 
Dimellus, 3500-4500 feet). 
Recognisable from the Arabian H. leplurus by the obsoleteness of the 
median inferior keel on the 1st and 2nd caudal segments, ete. 
(4) Butheolus insularis. 
Colour.—Tail and upper side of trunk olive black, appendages rather 
paler ; digits, distal end of legs, and ventral surface olive yellow. 
Carapace granular, its ante-ocular portion sloped; terga granular, especially 
along the posterior margin; terga 3-6 tricostate. wil incrassate to middle 
of 4th segment, inferior surface of segments 1-4 granular and furnished 
with four strong and granular keels, inferior surface of 4th and 5th smooth, 
impressed with large but shallow punctures, the former with very short 
granular keels in front, the latter granular posteriorly, its lateral keels only 
obsolete in front, upper surface of segments smooth; the Ist normally 
keeled, the 2nd with weaker and smoother keels, 3rd, 4th, and 5th punctured 
at the sides, the two former with scarcely a trace of lateral keels. Vesicle 
