27 



Sicyonella Borradaile (Aphareocaris Calm.). 



This characteristic genus has been somewhat curiously treated. In 1875 the Russian 

 zoolocist PAULSon established the genus Aphareus on a single species, A. inermis Pauls., from 

 the Red Sea ; it was referred to the family Penaeidse. As Paulson's paper is not only rare but 

 published in the Russian language, G. Nobili in 1906 fortunately translated the original description 

 of Aphareus into French and reproduced two of the figures; besides he suggested that the 

 o-enus ought to be referred to the Sergestidse. In 19 10 Borradaile established the genus Sicyo- 

 nella on a new species, 5". maldivensis Borr. ; he described the animal and added two figures, 

 but he did not perceive that the genus was identical with Paulson's Aphareus, and he referred 

 it to the subfamily Sicyoninae, of the family Penaeidse, which was rather unfortunate, and the 

 worst result of his classification is the misleading generic name. In 191 3 W. T. Calman proposed 

 the name Aphareocaris for Aphareus Pauls. which was preoccupied, but overlooked that the 

 genus was identical with Sicyonella Borrad., and according to the rules of priority the latter 

 name must be applied. Calman referred his form A. elegans Calm. to the family Sergestidae, 

 pointed out several important characters as to which the genus agrees with Sergestes, and 

 besides three eenene differences between it and Sergestes-, amoncr these the character based on 

 the male antennula? cannot be maintained, as later seen by Calman himself. He described a 

 single species, A. elegans, from the Torres Straits, and added 16 figures; his investigation and 

 his figures are so good that I have found it unnecessary to redescribe the type, its appendages 

 and branchiae or to draw new figures of the entire animal or most of its appendages. — In 

 19 14 Calman published an additional note, as Dr. H. Balss had drawn his attention to the 

 similarity between Aphareocaris Calm. and Sicyonella Borrad. He discussed the differences 

 between Borradaile's statements and his own in 19 13, suggested that his A. elegans Calm. 

 most probably had been established on an immature specimen, and that it must be considered 

 as a synonym to Sic. maldivensis Borrad., but whether this conclusion may be safe is to be 

 discussed later on. Finally Calman published a new figure of the petasma of the adult Sic. 

 maldivensis, which renders it possible to recognize this species with absolute certainty. 



Sicyonella Borrad. differs from Sergestes in the following characters. 1) The first pair 

 of legs have a well developed chela which is wanting in Sergestes; 2) second an third pairs 

 of legs have the chela much more developed with the fingers much longer in proportion to 

 the hand than in Sergestes; 3) the two last pairs of legs have seven joints, while in Sergestes 

 the seventh joint is absent; 4) telson has some pairs of dorsal spines, but no spines in Sergestes; 

 5) the processus ventralis of the male petasma is cleft into two very long branches, while it is 

 undivided in Sergestes. In all these characters, excepting perhaps the last mentioned, Sicyonella 

 stands nearer to the Penaeidae than Sergestes. The main differences between the Penaeidae and 

 Sergestes-Sicyonella together with figures illustrating most of the generic features of Sicyonella 

 are to be looked for in Dr. Calman's paper. 



Three species have been established in the literature, among which Sic. maldivensis 

 Borrad. can be determined with certainty by the aid of Calman's figure of the petasma in his 



