AUTHKOPOD FAUNA OF THE WEST INDIES. 379 



4. TiTTUs iNsi&Nis (Pocock). (PL XXIX. figs. 1-1 a.) 

 Isometrus insignis, Pocock, Ann, Nat. Hist. (6) iv. p. 67 (1889). 

 Locality. Pond de Jacques ia St. Lucia, collected by Gr. A. 



Ramage, Esq. 



This species is tlie largest of the genus, since it attains a 

 length of 110 mm. It is closely allied to T. americanus, but may 

 be at once recognized by the presence of only a minute tubercle 

 beneath the aculeus ; the aculeus, too, is only lightly curved as 

 compared with that of T. americanus. The male is unknown. 



5. TiTTUS OBTUStTS (KarscJi). (PI. XXX. figs. 10-10 a.) 

 Isometrus obtusus, Karsch, Mitth. Milnch. ent. Ver. 1879, p. 117) $• 

 ? Isometrus antillanus, Thorell, Etudes Scorpiol. p. 60, $ {cf. infra). 



(S . Colour (dry) ochraceous, variegated with black. Cepha- 

 lothorax ochraceous, the anteocular area and tubercle fuscous, 

 the fuscous patch with a flavous spot just in front of the 

 tubercle, the posterior keels also fuscous, with a fuscous spot 

 on the posterior margin outside the keel ; tergites ochraceous, 

 very indistinctly fusco-maculate ; the lower surface of the trunk 

 ochraceous, concolorous ; tail with its anterior three segments 

 uniformly ochraceous above, variegated with fuscous below, the 

 fuscous colouring increasing posteriorly, the fourth and fifth 

 segments and vesicle brunneo- fuscous above and below, deeper 

 below ; aculeus ferruginous, with black tip ; palpi fusco-maculate 

 above, the manus distinctly f useo-variegated externally, digits 

 black, with ferruginous tips ; legs with femora and tibiae fusco- 

 maculate ; tarsi pale. 



Trunk above granular; the anteocular and posterior keels of 

 the carapace coarsely granular, the median keel of the tergites 

 feebly granular; fourth and Mth. sternites finely granular ; keels 

 of the latter conspicuous and more coarsely granular. 



Tail more than six times the length of the carapace, expanding 

 from the base to the middle of the fifth segment; the upper 

 surface of the segments somewhat deeply excavated, the first with 

 10 keels, the second to the fourth with 8, the median lateral of 

 the second complete only posteriorly, all the keels well expressed 

 and coarsely granular, the superior especially strong and den- 

 ticulate ; the intercarinal spaces at the base of the tail nearly 

 smooth, but becoming gradually more and more granular towards 

 the posterior end ; the granules of the upper surface of the 



LINN. JOUEN. — ZOOLOQT, YOL. XXIV. 30 



