116 MR, W. K. BROOKS ON LUCIFER: 



Development of Lepas fascicularis and the 'Archizcea' of Cirripedia," by R. von 

 WILLEMOES-SUHM, Ph.D., Proc. Eoy. Soc., Dec. 9, 1875, pp. 129-130) to be the 

 Nauplius of a Barnacle, in all probability Lepas australis. 



GLAUS, on the other hand, believes that the Zoea has no such ancestral significance 

 (" Untersuchungen," &c., p. 31). That it has been formed by secondary modification 

 of the Protozoea, and that the views of MULLER and others, that the Zoea presents a 

 picture of the remote ancestor of the Malacostraca, is fundamentally erroneous ; and 

 not only this, but that the Proto'.oca itself is the result of the extreme secondary 

 modification of an ancestral form which GLAUS proposes to call an Urophyllopod, and 

 which he believes to have had the following characteristics (" Untersuchungen," p. 23) : 

 A greatly developed shield-like carapace, produced by a fold of the integument in the 

 region of the maxilke, and probably armed with median and unpaired spines ; two 

 maxillary segments and appendages, eight somites of the mid-body with appendages, 

 and six abdominal somites with swimmerets and telson ; a many-chambered heart ; 

 compound eyes, probably stalked ; a first antenna with sensory hairs ; locomotor 

 second antenna?, in which the exopodite was probably a scale ; the mandible probably 

 lacked a palpus ; the metastoma was represented by a pair of paragnathi ; the ruaxillre 

 had their basal joints modified for mastication, their endopoclites reduced to a jointed 

 palp, and the exopodite modified to form a scoop or scaphognathite for regulating the 

 flow of the respiratory current under the carapace. 



The following eight pairs of appendages were more like Schizopod feet, and each of 

 them carried a basal gill-plate ; the six pairs of abdominal appendages had large basal 

 joints with two branches and gill- plates. 



GLAUS believes that we may recognise in NeLaUa, which has stalked eyes, a scale 

 on the first antenna ; only one long flagellum on the second antenna ; a mandibular 

 palp ; a highly specialised, long jointed endopodite on the first maxilla ; two long 

 limb-like rami on the second maxilla ; eight pairs of phyllopod-like thoracic limbs with 

 jointed endopodite, flat, spiny exopodite and gill ; six pairs of pleopods, the last two 

 rudimentary ; and a seventh somite between the sixth abdominal somite and the 

 deeply-forked telson (" Ueber den Bau und die Systematische Stellung von Nebalia," 

 Zeit. f. Wiss. Zool., xxii. p. 323-330), a very slight modification of this ancestral 

 Urophyllopod. 



He gives on pages G9-71 of his "Untersuchungen," &c., a long, minute, and 

 extremely ingenious explanation of the way in which this Urophyllopod stage of 

 development became converted by secondary modification into the Malacostracan 

 Protozoea, and afterwards, by still greater modification in the same direction, into 

 the typical Zoea of the higher Decapods. 



The facts which have been detailed and tabulated with reference to the metamor- 

 phosis of the Sergestidre and Penceus seem to substantiate at least a portion of this 

 view, and to show that the typical Zoea is a secondary modification of the Protozoea ; 



