HA RD WICKE' S SCIENCE- G OS SIP. 



quite normal ; several longitudinal "head-retractor" 

 bands run through the body, and some five transverse 

 cords encircle the trunk at equal intervals. The 

 foot-glands are a pair of remarkably long, club- 

 shaped, turgid organs, extending frcm the toes right 

 up into the trunk, to the level of the summit of the 

 contractile vesicle ; their ducts plainly open as pro- 

 jecting tubules at the extremities of the large swollen 

 toes. These latter are of peculiar and distinctive 

 shape (see fig. 125) and will, I think, with their 

 nipple-like ducts, sufficiently identify the species ; 

 the foot, of some four joints, is short, and in width 

 not more than one-third the greatest width of the 

 trunk. 



This creature bears a certain resemblance, in its 

 long foot-glands, and in the shape of the gastric glands 



them. What I wish to do is to give as thorough and 

 comprehensive a description of each one as possible and 

 to indicate some of the more important habits con- 

 nected with their life-history. My notes and diaries 

 will be called into account here, together with original 

 drawings from life of the various ones under consider- 

 ation. 



The subject of my first paper, as will be seen above, 

 is the common Cyclops, a creature familiar to all 

 microscopists, and indeed it is scarcely possible to 

 take a dip in any pool, clear or otherwise, without 

 taking a few. But let us see its position in the 

 animal world. Cyclops is a genus of the Branchio- 

 poda, the latter being the first order of the division 

 Entomostraca of the class Crustacea. It is distin- 

 guishable as follows : — The thorax is segmented. 



A¥> 



Fig. 126. — Cyclops quadricornis. i, female C. quadricornis : A, superior antennse ; li, inferior ditto ; c, eye ; D, internal ovaries : 

 I, external ovaries. 2, male, C. quadricornis, var. rubens : F, heart: G, male organs. 3, young, recently hatched. 4, male 

 of type. 5, second pair of foot-jaws : H, external portion ; K, internal portion. 6, rudimentary legs. 7, mandible : L, serrated 

 seta; M, palp-filaments. 8, first pair of foot-jaws, g, Inferior antennae of male. 10, thoracic legs, ditto. N.B. — The figures 

 of enlargement are not mathematically correct, but near enough to serve the purpose. 



and toes, to a form described by Dr. Plate as para- 

 sitic on Gammarus, under the name of Furcularia 

 gammari, but is evidently not identical therewith. 



Length, about ^ inch. 



Sp. Chars : — Body plump ; eye absent ; gastric 

 glands angular ; foot glands remarkably long, turgid ; 

 foot short ; toes short, thick, swollen cones, with 

 projecting duct-orifices. 



POND LIFE STUDIES. 

 No. I. — Cyclops quadricornis. 



By H. DURRAN'T. 



IN this and the following papers I shall try to give 

 some idea of a few of our commonest and 

 smallest pond inhabitants. I select the commonest 

 because they are easily obtainable by those who have 

 little time at their disposal for collecting, so that they 

 will be able to procure them without trouble, and thus 

 follow me in my remarks with the living animal before 



There is only a single eye, and that central, and 

 placed on the anterior and largest segment. Body 

 gelatinous, rather oval, divided into an anterior and 

 a posterior portion. The first contains head and 

 thorax ; the latter the forked tail. The anterior 

 portion of the body consists of four segments, of 

 which the first takes up about two thirds, and includes 

 a portion of the thorax. These are covered by a 

 scale common to both. On the frontal part are 

 situated the solitary eye, the four antennae (two 

 superior and two inferior), two mandibles furnished 

 with either a simple or branched feeler, two jaws 

 (external mandibles of Jarine), and four feet, each 

 divided into two cylindrical stems, either fringed with 

 hair or bearded. Jarine compares the anterior pair 

 to a kind of hand. The three remaining segments 

 each give rise to a pair of legs. The two superior 

 antenna; are the longest. They are articulated, 

 setaceous and simple. In the males these antenna: are 

 frequently contracted in places with swellings between. 

 The antennules (lower antennce) are filiform and 



