Dear Sir,

I am pleased to learn that any of the particulars contained in my last letter interested you, and I assure you that I shall be glad at all times to communicate such facts in the natural history of the Araneidea as have come to my knowledge.¹

As Atypus Sulzeri, Theridion tinctum and Epeïra conica do not occur in this locality,² I am incompetent to form an opinion with regard to the probable numerical proportion of the sexes of those species respectively. The sexes of Thomisus bifasciatus do not seem to present any marked difference as to numbers;³ the males undoubtedly are most frequently seen, but this circumstance may be ascribed with much probability to their being more erratic than the females, and this remark is applicable to numerous species.⁴ The females of Thomisus floricolens and Tho. citreus appear to be more abundant than the males, which differ from their mates remarkably both in size and colour.⁵ The males of Sparassus smaragdulus and Epeïra bicornis differ conspicuously from the females in colour;⁶ they are smaller also than the latter sex, and of less frequent occurrence.

Decided differences may be observed in the colours and in the designs formed by their distribution in the sexes of the following species; Philodromus dispar, Theridion Carolinum and Linyphia fuliginea;⁷ the males are smaller also and appear to be fewer in number than the females. The figure of the male Philodromus dispar given in the “History of British Spiders” was made from a specimen whose colours had been affected by the spirit in which it was preserved (see the description of this species, pt. 1, pp. 91, 92).⁸

The males of species comprised in Dr. Leach’s genus Nephila (a division of the family Epeïridæ)⁹ apparently bear a very small proportion both in number and size to the females, from which they differ also remarkably in colour. These facts are strikingly illustrated in the “Aranéides des Iles de la Réunion, Maurice et Madagascar,” by Auguste Vinson, pl. V, figs. 1 & 2; and pl. VI, figs. 1 & 2.¹⁰ M. Vinson appears to be the only person who has captured the male of Scytodes thoracica, a species widely distributed and far from being uncommon.¹¹ As a rule, I think that male spiders differ more decidedly than females from the ordinary colouration of the genera to which they belong.¹²

Let me caution you not to attach too much importance to the statements of an individual who has resided for thirty-five years in a secluded valley, where there are neither public libraries, museums, nor students of any department of zoology, and who, consequently, has to depend mainly on his own resources.

I am, dear Sir, | very truly yours | John Blackwall.