ON THE COLLECTION OF SPECIMENS OF MYRIA- 

 PODS. PHx\LANGIi)^, &c. 



Academy of Natural Sciences, 



TMladelphia, February 13, 1866. 



Dear Sir : My excuse for troubling you with the following- communication 

 must be my great desire to render more complete the already published mono- 

 graphs of the North American myriapods or centipeds, and also to obtain mate- 

 rial for a similar memoir on the phalangidje or "harvestmen" of the United States. 

 As you are aware, the myriapods are divided into two great sub-orders, the more 

 highly organized of which live on animal food, while others find their sustenance 

 in decaying vegetable substances. These two sub-orders may be distinguished 

 at a single glance by the most inexperienced eye ; the first, the true centipeds, 

 by their flat body, each segment of which has but a single pair of legs, and then 

 ahead, armed with a formidable pair of jaws ; the second, the millepeds by 

 their body being more or less terete or cylindrical, with two pair of legs to each 

 segment, and the jaws of their head not being very apparent. The former may 

 be found under stones, logs, beneath the bark of dead trees, about Avood piles 

 and out-houses, in fact, in almost every place which affords them shelter, and is 

 not too wet. The larger species of this group are probably all known, but 

 specimens, with the localities from which they have been obtained, are valuable, 

 as they throw light on the problem of geographical distribution. Among the 

 smaller species, at least the long, narrow- bodied species, (geophilidse,) there are 

 probably many species still unknown, and of these I would especially solicit 

 collections. 



The millepeds are to be looked for in decaying wood, beneath the bark of 

 old logs, &c , as well as in similar situations with the last. The number of facts 

 still unknown respecting these myriapods, and of species new to science, is 

 probably very great, so that collections of them are even more valuable than 

 those of the smaller centipeds. As in most other cases in natural history, the 

 small specimens are the most valuable, affording the largest per cent, of un- 

 known and rare species. . When a myriapod is captured it should be thrown 

 into alcohol, the only precaution necessary being to have the alcohol very strong 

 in the case of millepeds, since they are very apt to fall to pieces if the preserva- 

 tive fluid is weak. It is not necessary to separate the species, but the general 

 locality should always be marked both by a label pasted on the bottle, and also 

 by one placed in the inside, the collector's name being distinctly written so as 

 to facilitate acknowledgment. 



The phalangidiB, "harvestmen," or "daddy long-legs," of the schoolboys, resem- 

 ble the true spiders, from which they are distinguished by the great length of 

 their slender legs, by their abdomen being sesile, i. c, attached to the whole 

 breadth of the anterior portion of the body, (the cephalothorax,) and unprovided 

 with a spinning apparatus, as well as by their head, having a single pair of eyes, 

 elevated on a common peduncle or process, and being armed with a pair of two- 

 fingered mandibles. The female deposits her eggs in crevices, in Avails and 

 rocks, beneath stones, &c., in the autumn, and then dies. The following spring 

 the eggs are hatched and produce minute individuals, which reseinble the ma- 

 ture specimen. These grow through the summer, and reach their full size iu 

 the early autumn, when the sexes pair. They are preferably nocturnal in their 



