210 Miscellaneous, 



On March 13, 1894, females -were found with cj^gs, which are 

 pink in colour. The number of eggs laid by one female is very 

 great ; I estimated tliera at a thousand. From the Mesilla Valley 

 specimens I bied some numbers of a Chalcidid parasite, the Aphycus 

 ceroplastis of Howard. 



Looking over the above list of Chihuahua State insects, it will be 

 seen that the Xearctic types largely preponderate, and that some few 

 are even boreal. But it is proper to state that several of the species 

 taken have not yet been identitied ; and as the specimens were 

 mostly submitted to specialists who are much more familiar with 

 the Xcarctic than the Neotropical fauna, it may be assumed that the 

 unnamed species were probably largely Neotropical. Consequently, 

 had everything found been named, the percentage of Neotropical 

 types might have been larger. 



The localities cited are all ovtr KUIJU feet above sea-level ; Juarez 

 is about 3700 feet, Montezuma about 4500 feet, Damalayuca about 

 4200 feet, Ojo Caliente about 4200 feet, Ortiz about 3800 feet. 



Las Graces, New Mexico, U.S.A., 

 Nov. 13, 1894. 



On the Nutrition of Ttvo Gomiucnsah (Nereilepas and Pinnotheres). 

 By M. Hexki Corpix. 



It is a well-known fact that in the whelk-shells inhabited by 

 hermit-crabs the annelid Nereilepas fucata is very frecjuently found. 

 This worm takes up its abode in the first whorls of the spire — that 

 is to say, in a chamber which is almost completely closed by the 

 posterior portion of the crab. It is, however, very well develoi)ed, 

 in no way foul, and is, so to speak, resplendent with health. 

 Herein there is nothing that need astonish us, as it is admirably 

 protected against injuries and enemies from without. But the 

 (juestion arises, as to how it is able to obtain food. It is generally 

 supposed that it is contented with consuming the excrement of the 

 hermit-crab, which is voided in the very spot in which it is found. 

 With a view to ascertaining if this is really the case I made 

 various observations and experiments, which show that this hypo- 

 thesis has no foundation in fact. 



Let us actually examine a hermit-crab having a Ncreilei>as as its 

 co-tenant. The crab has two principal modes of feeding. Under 

 ordinary circumstances it is content to devour the particles which 

 are brought into contact with its mouth by the rapid movements of 

 its appendages : the refuse of these matters after digestion passes 

 to the exterior in the shape of a cylindrical roll, more or less elon- 

 gated, about 1 millim. in diameter, and easily to be distinguished 

 from the faeces of the worm, which are filiform. If the worm 

 devoured these evacuations, it is very evident that they would not 

 be seen to pass out of the shell. During the whole of the time that 



