ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 183 



time the rostrum is seen, immediately followed by the Latus superius. 

 Then the upper row of Latera appear, and then the small scales of the 

 stalk begin to form. The growth of the animal, especially that of the 

 stalk, is almost entirely restricted to the narrow transition-zone from 

 capitulum to stalk. In all probability the ancestral form of the stalked 

 Cirripeds had only five thickened parts of the mantle, Darwin's 

 " primordial valves " — first chitinous and subsequently calcareous. From 

 this primitive type the pedunculated Cirripeds seem to have developed 

 along two lines. One leads to the extinct Archseolepas and Loricula, 

 and to the recent genera Jlitella (possibly the starting-point of the 

 sessile acorn-shells) and ScalpeJlum. The other line has given rise to the 

 other genera of stalked Cirripeds, which have retained the five primordial 

 valves or even reduced the number. J. A. T. 



Melanin in Crustacea. — J. Verne (Gomptes Bendus Soc.BioL, 1920, 

 83, 7G0-2). In the epidermis of Brachyura there is a yellowish pig- 

 ment from which a melanin can be obtained experimentally. The 

 pigment is formed on a mitochondrial substratum by mesenchyme cells, 

 disposed in a perithelium around blood-vessels. These chromatophores 

 move to the surface, and in parts exposed to light their contents are 

 changed into insoluble melanin. The original yellowish pigment is of 

 the nature of amino-acid, and the transformation into melanin depends 

 on the presence of tyrosin. The chromatophores are amino-acidophores 

 physiologically. J. A. T. 



Carotin of Crustacea. — J. Verne (Gomptes Rendiis Soc. Biol., 

 1920, 83, 988-9). The carotins of Crustaceans oxidize very rapidly. 

 But Merejkowski's idea that this facile absorption of oxygen pointed to 

 a function like that of hasmoglobin is negatived by Krukenberg's 

 observation that carotin once oxidized does not readily part with its 

 oxygen as oxy-hfemoglobin does. The result of oxidation is a complex, 

 which includes a product like cholesterin. This may account for the 

 presence of cholesterin in Crustaceans. It is absent from the epidermis, 

 abundant in the hepato-pancreas, and occurs in small quantity in the 

 blood. The oxidation of carotin takes place very slowly in tissues pro- 

 tected by a thick integument. J. A. T. 



Red Pigment of Crustaceans. — J. Verne {Gomptes Bendi/s Soc. 

 Biol., 1920, 83, 903-4). This pigment has received many names — 

 zoonerythrin (Merejkowski), vitellorubin (Maly), lutein or lipochrome 

 (Krukenberg, Heim, Newbigin). It is chemically and spectroscopically 

 like carotin. It is a hydrocarbon, with the carbon and hydrogen in the 

 proportion 5:7. The formula C^^^Hj^ is suggested. Like vegetable 

 carotin it forms along with iodine a characteristic violet-brown pigment. 



J.A.T. 



Annulata. 



Australian Polychseta. — 'W. A. Haswell {Proc. Linn. Soc. N.S.W., 

 1920, 45, 90-112, 4 pis.). A systematic account of members of the 

 families Syllid*, Eusyllid^e, and Autolytidi£, including the following 



