378 ME. E. I. POCOCK ON THE 



Althougli Dr. Karscli looked upon this Scorpion merely as a 

 variety of T. americanus — an opinion in which he has beeu 

 followed by Prof. Kraepelin — I think there can be little doubt 

 of its distinctness. When first I put forward this suggestion, I 

 had only seen a few examples of the form to which the name 

 androcottoides would apply ; but during the past three years 

 the British Museum has received many others, all of -which 

 justify the belief in the distinctness of androcottoides from 

 americanus. 



Apart from sexual characters which are very distinctive, this 

 species may be recognized from americanus, as from all the 

 Antillean species of the genus, by the fusion of the inferior keels 

 of the posterior caudal segments. 



3. TiTTUS AMEEic^Kus {Linn.). (PI. XXIX. figs. 2, 2 J.) 



Scorpio americanus, hinn. Mus. Adolph. Frid. p. 84 (1754), 



Scorpio europseus, Linn. Syst. Nut. ed. 10, p. 625 (1758) ; De Geer, 

 MSm. vii. p. 344, pi. xli. figs. 5-8, $ . 



Scorpio obscurus, Gervais, Arch. Mus. iv. p. 219, $ . 



Scorpio forcipula, id. loc. cit. p. 221, pi. xi. fig. 26, J . 



Isometrus americanus, Thorell, Etudes Scorpiologiques in Aiti Soc. 

 Ital. xix. p. 90 ; Bertkau, Mem. Ac. Belg. xliii. p. / ; Karsch, Mitth, 

 Miinch. ent. Ver. 1879, p. 113 ; Pocock, Ann. Nat. Hist. (6) iv. 1889, 

 p. 57. 



Phassus americanus, Kraepelin, Jahrb. Hamb. Wissen. Anstalteny viii. 

 p. 112 (1891) (at least in part.) 



This species, which is widely distributed throughout the 

 northern parts of South America, occurs in Hayti and Porto Eico 

 {teste Kraepelin and Mas. Brit.). 



Note. — At present, in spite of the opinions of some of my 

 contemporaries, I decline to admit the species named T. cetJiiops 

 and T. longimanus of C. Koch (Die Arachn. xi. pp. 856-857) 

 amongst the synonyms of T. americanus. My reasons are 

 briefly these : — (1) C. Koch records the specimens of these 

 species from Java, where T. americanus can only accidentally 

 occur; (2) these two so-called species are clearly to me sexes of 

 one and the same form, which must be called cBtTiiops, and their 

 sexual characters are not those of T. americanus. 



