BIOLOGY AND STRUCTURK OF HYDROPHILUS CARABOIDES 



629 



Scuta prothomcica eon- 

 creta, completa, integra. 

 Scuta mesothoracica dis- 

 creta, tergum medium oc- 

 cupantia, triangula, apicem 

 truncatum versus con- 

 structo-attenuata. Scuta 

 metathoracica discreta, in- 

 completa, apice incurva. 



Praeterga abdominis in- 



tegra 



Terga 



The prothoracic tergite has the 

 shape of a continuous shield of 

 an ahiiost regular quadrangle, 

 the posterior corners l)eing 

 obliquely cut or rounded (the 

 tergite of the mature larva of 

 H. c a r a b o i d e s is conspicu- 

 ously narrowed in front and in 

 outline much like a truncated 

 cone). The meso- and meta- 

 thoraces bear each on their ter- 

 gites two triangular shields, the 

 apex of which is not bent. 



Abdomen densely hairy (Text- 

 fig. 1). Tergites with four warty 

 tubercles which are also covered 

 with hair, and wdth a long seta 

 on the summit. Before the 

 middle pair of tubercles there 

 is a pair of brown shields of 

 strong chitin, also bearing long 

 setae. 



Pleural appendages in shape 

 of cylindrical prominences, and 

 densely covered with hair, resem- 

 bling a lamp-brush. From the 

 summit of each appendage there 

 emerges a long and thin seta 

 (Text-fig. 1). 



Above the base of each lateral 

 pleural appendage there is a 

 small warty tubercle with a long 

 seta. 



The examination of more advanced larvae of Hydro- 

 philus caraboides, i.e. such that had already moulted, 

 convinced me of the accuracy of Schiodte's description. The 

 antennae of such larvae are in fact hairy on their inner edges, 

 and the base of the lamella of the under-lip has a dentate edge. 

 The long setae on the tips of the pleural appendages are 

 partially present but not conspicuous. 



On the whole one might say that from the egg of H y d r o - 

 philus caraboides emerges a larva which in its successive 



obscurius 

 plicata, scutis verruciformi- 

 bus, cylindricis. Appen- 

 dices pleurarum abdominis 

 praeter octavum par elon- 

 gatae, inaequales, ciliis 

 gracillimis vestitae, n a t a - 

 toriae; appendices oc- 

 tavi paris deorsum flexae, 

 acuminatae, sinuosae, sus- 

 pensoriae. 



