1886. ] Recent Literature, 1033 - 
ties are, however, but a slight test of the value of any contribu- 
tion to science, and the present instance is no exception. The 
principal feature of this paper is the extent to which it increases 
our knowledge of the bathymetrical distribution of the forms 
enumerated, and points out the coincidences between depth of 
occurrence and points of structure. These lists record forty- 
three species as coming from below the 1000 fathom line, while 
twenty-two were taken from a depth greater than 2000 fathoms. 
The greatest depth recorded is 2949 fathoms, and from a single 
station of this depth, about 350 miles east of the mouth of the 
Chesapeake the trawl brought up Acanthephyra agassizit, A. brevi- 
vostris, Notostomus vescus, Hymenodora glacialis, Parapasiphaé 
sulcatifrons, Hepomadus tener and Sergestes mollis. Of the per- 
tinence of the first of these to these great depths some doubt is 
expressed, as at another time one was caught swimming at the 
Surface. All of these forms it is to be noted are macrurous, 
Some of the deep-sea forms are colorless, but most are of some 
bright shade of red or orange. Their eyes have undergone a 
careful superficial examination. In some the black pigment, the 
corneal facets and the like are much as in shallow-water forms, 
€xcept that occasionally the eyes are smaller. In Munidopsis and 
Pentacheles the visual elements are apparently lacking, while in 
others the pigment is light colored and the visual elements are 
reduced in number. In some of the deep-water shrimps there is 
a curious accessory organ borne on the eye-stalks which may be 
Phosphorescent in its nature. It certainly deserves careful histo- 
logical examination at competent hands. In the eggs, too, a 
peculiarity is noticed. Among the shallow-water decapods the 
eggs are usually so small that it is a matter of some difficulty to 
Cut sections of them, but in these deep-water forms they attain a 
very considerable size, those of Parapasiphaé sulcatifrons having 
a diameter fifteen times those of the common soft-shelled crab, 
Neptunus hastatus. 
We have a little fault to find with the present paper. The 
first is that which is found in all of the Fish Commission publi- 
Cations, but which here is not as bad as in embryological work— 
=~ the use of process cuts. We notice a tendency to the creation 
of new families which hardly seems to be warranted. Until we 
know more of the morphology of the crustacean gill it hardly seems 
advisable to make gill-structure alone the basis of forming higher 
_ groups and separating widely species which are in all other re- 
_ Spects closely allied. 
_ SEDGWICK AND Witson’s Brotocy.'—We have several guides to 
laboratory work in biology, but the great fault with all is that 
_ they stick too closely to the anatomical and developmental sides 
a GS SRE Ding SA a PS cE eR Ps ee fe ee ee E S T ee a: 
= SG a a ag EEEE a i i ah S i och 
Ct Sie eta = ñ 5 z 5 = = 
| General Biology. By WILLIAM T. SEDGWICK and EDMUND B. WILSON. New 
York, H. Holt & Co. pp. vi + 193. 1886. 
VOL. Xx—wno. XLN. €9 
