ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 427 
or in some cases perhaps physical process. From the relative or 
absolute blindness of luminous Copepods, Giesbreclit concludes that the 
biological use of the luminosity is probably to mislead such enemies as 
fishes. 
Finally, the author discusses the pigmented knob on one side of the 
first thoracic segment of Pleuromma. We have not space to do more 
than state his conclusion that it is not an eye, nor a luminous organ, 
but a gland of unknown function. 
Annulata. 
Oligochaeta of the Pacific Coast of California.* — Mr. G. Eisen 
describes three Oligochmtes from the Pacific Coast ; the first of these is 
the type of a new genus which he calls Phoenicodrilus (P. taste sp. n.) ; 
it contains small slender terrestrial forms closely allied to Ocnerodrilns , 
from which they differ only in the absence of a prostate. A temporary 
generic diagnosis is offered, and a full account is given of the anatomy 
of the only species which is as yet known. The absence of a prostate 
is rightly considered to be a fact of considerable interest, and the author 
thinks that it clearly demonstrates that the presence or absence of this 
organ cannot be taken for the foundation of families of Earthworms. 
The absence of a prostate in an Ocnerodrilid is not unexpected, for the 
species of Ocnerodrilns may themselves be arranged in a series according 
to the size of this organ. Ocnerodrilns occidentals has a very large one, 
while 0 . hendrici has a most diminutive one, .so that the absence in 
Phoenicodrilus is only one step further. Mr. Eisen thinks that this fact 
should have some influence upon our views of the classification of the 
Oligochseta, and that several genera or families which have hitherto 
been considered far apart solely on account of the presence or absence 
of a glandular prostate must now be brought closer together. 0 . taste 
was first found at an altitude of 4000 feet, but since then it has been 
found almost on the level of the ocean. It lives in damp soil and occurs 
in great numbers. Pontodrilus michaelseni is the only species of the 
genus which has as yet been found on the Pacific coast. It inhabits a 
very narrow moist line between the high tide and dry soil of the shores 
of the Gulf of California near Guay mas, Mexico. It differs from all 
other species which have been referred to this genus, with the exception 
of P. marionis , in possessing a glandular crop occupying somites xiv. 
to xvi. While Perrier only found blood-glands in the blood-vessels, or at 
the end of the capillaries investing the nephridia, Eisen has found them 
in this species only in the capillaries of the salivary and septal glands, 
where they occur in very large numbers. At the same time it is to be 
noted that individual specimens vary in the number of blood-glands 
which they possess and, as Perrier has shown, they are of all sizes and 
shapes. A useful table is given in which the chief anatomical characters 
of the species of Pontodrilus and Photodrilus are compared. The third 
species described is Eclijpidrilus fragilis, of which Eisen has already 
given some account. His present researches show that the species is 
less aberrant in its anatomical characters than he first supposed, and he 
is now inclined to consider that the family of the Eclipidrilidse is not 
isolated, but rather a sub-family of the Lumbriculidse. 
* Mem. Cal. Acad. Sci., ii. (1895) pp. 63-122 (15 pis.). 
