ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 885 



larvae shall be directed forward and be in mutual apposition ; eacb 

 division contains twelve, each story, twenty-four ; every egg is 

 enveloped in a glutinous recess. The capsule itself is impermeable 

 to water. The ootheca is built up of a foamy liquid which is spread 

 out by the aid of the ends of the elytra ; the abdomen works it up 

 by regular movements and lays it on layer by layer, assisted by the 

 cerci ; the ova are expelled by the abdomen, accompanied by a 

 certain amount of frothy fluid which forms the alveoli in which they 

 are to lie. 



The uselessness of the legs at the time of the emergence of the 

 larvae is compensated for, as observed by M. de Saussure, by back- 

 wardly-directed spines which, owing to movements of the body, push 

 the insect forward, in the same way as an ear of rye may be made to 

 travel over cloth, but the spines are placed in the cerci, not on the 

 abdomen ; the legs also are covered with strong spines. The upper- 

 most eggs are the first hatched. Death sometimes occurs from the 

 closing of the operculum over the opening before the larva is quite 

 out. The retention of the larvae by their cerci and abdomen on the 

 surface of the capsule for some days after extrusion is a remarkable 

 feature of the process ; they are only released by the shedding of the 

 skin in vrhich they emerged, and which is left attached to the capsule ; 

 they are now very active and devour small insects greedily. The 

 silky threads which they bear do not represent the cerci, as has been 

 supposed ; they appear to be used in facilitating the first moult by 

 securing the larvae to surrounding objects. 



■y. Araclinida. 



Observations on Acarida.* — P. Kramer first deals with the mode 

 of reproduction in Dermaleichus stylifer ; when a pair are found in 

 copula, it is seen that the male takes such a position that the penis 

 must needs be, as it is, longer than the abdominal appendages of the 

 female. In dealing with the development of Cheyletus eruditus he 

 points out that in it, as in the Spiders, there is a true care for the 

 developing ova ; if an attempt is made to remove the eggs the female 

 attempts to seize the instrument with its palpi. Development com- 

 mences by a cleavage of the yolk, which is gradually overgrown by a 

 homogeneous blastema ; and the anterior pole becomes distinguished 

 by an aggregation of the yolk material. On the whole, the method 

 of development calls to mind Claparede's account of Myohia muscidi, 

 where that investigator found that a deutovum and a tritovum were 

 formed. 



After a comparison of the genera Sepis and Zercon with Gamasus, 

 the author proceeds to a description of Scirus taurus n. sp., and of 

 GlycipJiagus ornatiis, n. sp. In the genus Bdella the following new 

 species are described : B. crassirostris, B. longirostris, B. lapidaria, 

 B. arenaria, B. silvatica, and B. capillata. The note concludes with 

 some observations on the systematic characters of the sub-family 

 Eupodidce, and of its genera Scyphius and Eupodes. 



* Zeitschr. f. Ges. Natiuw., liv. (1881) pp. 417-52 (2 pis.). 



