ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 61 



be compared to the skeletons of certain diatoms. There are tliree 

 pairs of very small ovaries, placed in the 3rd, 9th, and 10th segments ; 

 the oviducts appear to be represented by two very minute and delicate 

 organs in the 9 th segment ; they are funnel-shaped, and the globular 

 internal orifice is devoid of cilia. The efferent ducts are of enormous 

 size, and each consists of two saccular ducts of nearly equal size, 

 connected at the extremities by a short narrow tube, which is sm-- 

 rounded by spiral muscles ; the longer of the two is the one which is 

 directly connected with the body- wall, and it has near its inner end 

 three very minute circular orifices. Inside this duct there is another, 

 which is always full of spermatozoa, and evidently serves as a true 

 seminal vesicle. " The total absence of efferent funnels is a character- 

 istic of great value, not met with anywhere else in this class of worms, 

 and which places Eclipidrilus in its decidedly isolated position." 



The single known species is called E. frigidus, and has only as yet 

 been found in the high Sierra Nevada of California at 10,000 ft. or 

 higher. It is a true limicolide Oligochsete, with its closest relations 

 with the Tubificidse and LumbriculidEe. 



Ctenodrilus pardalis.* — J. Kennel, after a description of the 

 external form of this Annelid, in which he directs attention to the 

 variations in the arrangement of the setae, describes the histological 

 characters ; the central nervous system, throughout its whole length, 

 lies in the epidermis, and exhibits the very simplest arrangements, 

 comparable more to what is seen in Polygordius and Saccocirrus than 

 in any higher form. The supra-oesophageal ganglion is formed by a 

 transverse bridge of fine dotted substance, in which no fibrous bands 

 are to be detected, and of surrounding ganglionic cells, which are 

 collected into two lateral groups, without, however, being sharply 

 separated off from the epithelial cells. On either side, the dotted 

 substance of the ganglioa is continued into a fine commissure which 

 traverses the epidermis and becomes connected with the ventral 

 medulla ; these bands appear to be devoid of any ganglionic invest- 

 ment. The ventral cord presents very much the same histological 

 characters as the dorsal ganglia, for, just below the basal membrane 

 of the epithelium, there is a fairly well developed cord of dotted sub- 

 stance, with cells at its sides, which pass without any distinct demar- 

 cation into the epidermal cells, between which and them no absolute 

 difference can be said to exist. No peripheral nerves were detected, 

 but, though their absence is not to be assumed, there would appear 

 to be no absolute necessity for their existence ; inasmuch as it is pro- 

 bable that here, as in many of the lower animals, the elements which 

 form the tissues have many of the properties belonging to a simple 

 living cell, and, among these, irritability. The only sensory organs 

 are the two small ciliated pits which are placed at the sides of the 

 cephalic lobe, on the dorsal ganglion ; their depression is very shallow, 

 and only a few cells take part in their formation. 



Similarly, a great simplicity is to be seen in the musculature ; 

 immediately below the fine basal membrane of the epidermis there is 



* Arbeit. Zool.-Zoot. Inst. Wiirzburg, v, (1882) pp. 373-429 (1 pi.). 



