1884.] NATURAL SCIENCES OF PHILADELPHIA. 153 



and none that it proves more protective than the ordinary 

 araneal cocoonery. 



Mr. Webster has found these mud-cocoons throughout the 

 whole range of Illinois, a State of great longitudinal extent. 

 Two balls from Southern Illinois are larger than the others, and 

 composed of yellowish earth, but Dr. McCook had not yet suc- 

 ceeded in breeding anything from them. The balls from Central 

 Illinois are made out of the rich black soil common to the prairies ; 

 the spiderlings hatched were from this section. He had named 

 the species provisionally Micaria limnicunae {limnus^ mud; 

 curiae, a cradle), but thought it possible that Hentz may have 

 described the species among some one of his genus Herpyllus. 

 The young have pale yellow abdomens, of uniform color, and legs 

 and cephalothorax of a uniform livid or stone-color. The adults 

 (females) are of a uniform dark amber color ; the cephalothorax 

 glossy, leathery and smooth. The cephalic part is depressed 

 below the thoracic part, sloping forward and downward. The 

 body length is about one-fourth inch. 



The only spider cocoons known to the speaker at all resem- 

 bling those of Limnicunae he had collected in a field at Alexandria 

 Bay, New York, on the St. Lawrence River, 1882. They were 

 attached by very loose spinning-work to the underside of stones. 

 But the external case instead of being mud, was a mass of agglom- 

 erated particles of old wood, bark, leaves, blossoms, the shells 

 and wings of insects, etc. These were evidently gnawed off, 

 gathered and placed together, and then held in position by deli- 

 cate and sparsely-spun filaments of silk. Two of these chip-balls 

 were opened, and contained whitish cocoons similar to those in 

 the mud-balls of Limnicunae ; another had within it the charac- 

 teristic cell of some hymenopterous parasite, containing a dried- 

 up pupa. A very thin veneering of yellow soil enclosed the 

 silken case, but otherwise no mud was used. He put aside three 

 specimens which remained, in the hope of hatching out and thus 

 determining the species of the maker, but nothing ever appeared, 

 and he had not wished to destroy such interesting specimens for 

 the sake of knowing the condition of the interior. But on com- 

 paring these specimens with those of Mr. Webster as now before 

 him. Dr. McCook believed that they were the work of closely 

 related, or perhaps even the same species. 



It is quite common for spiders of various and widely separated 

 families to give their cocoons a protective upholstering of 

 scraped bark, old wood, etc., and not unusual to find species 

 that cover their egg-nests wholly or in part with mud. But the 

 speaker was not aware that an}^ species had yet been published 

 as making cocoons like either of the above-described forms. He 

 believed, therefore, that the facts were wholly new to science — 

 certainly they were new to the field of American Araneology. 



The following were ordered to be printed : — 

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