Dr. F. Miilier on the Development of the Stomapoda. 17 



only smell remains. This cannot be deficient in animals which 

 may be attracted by a strong-smelling bait. If we now consider 

 how the inner antennse of Crabs, Porcellance, and Paguri are in 

 almost uninterrupted motion, as it were feeling through the 

 water, which passes over them in a constant stream, by short, 

 rapid strokes with their tufts of bacilli, we must consider them 

 just as well adapted for the perception of odours as the parts in 

 the basal joints of the inner and outer antennse hitherto indi- 

 cated as organs of smell appear ill fitted for that office, the latter 

 wanting the most indispensable requisite of an organ of smell, 

 namely, the ready and free access of water. 



To return to our larva. 



The posterior antenn<B likewise spring from the margin of the 

 body at the posterior angles of the above-mentioned quadran- 

 gular part bearing the eyes and antennse; they are scarcely 

 shorter than the anterior, and consist of a two-jointed stem and 

 a laminar apical joint, somewhat dilated and beset with bristles 

 towards its rounded extremity, equal in length to the stem, and 

 directed backwards in repose. The jointed flagellum of the 

 mature Stomapod does not appear. 



The mouth is situated in the middle between the four lateral 

 angles of the carapace ; before it is a large helmet-shaped labrum ; 

 at its sides the mandibles (fig. 4), apparently destitute of palpi, 

 each armed with three pointed teeth, which increase in length 

 backwards, and are again finely denticulated on their anterior 

 margin. Then follow two pairs of weakly developed maxillce ; 

 the anterior (fig. 5) has two branches, each armed with three 

 spine-like bristles and a minute palpus ; the posterior (fig. 6) 

 is a completely unjointed longish stump, with a few bristles at 

 the end. 



The feet of the following pair are thin, slender, and five-jointed, 

 and reach to the sides of the mouth anteriorly, nearly to the 

 origin of the posterior antennse ; their last two short joints are 

 usually turned inwards and backwards. 



Close behind these spring the Xd^v^e prehensile feet. The little 

 animal likes to carry them widely extended as it hangs perpen- 

 dicularly in the water (fig. 1). The basal joint then reaches 

 outwards to the margin of the carapace; the second and third 

 form a stalk slightly thickened towards the extremity, and 

 1 mill, in length, which, being directed obliquely upwards, 

 reaches to the level of the eyes ; the fourth joint is short and 

 not distinctly separated, and unites the stalk with the horizontal 

 palm, 1 mill, in length, which is slightly clavate and bears on 

 its straight inner margin one long spine and a series of very 

 short ones. Lastly, the claw is slightly curved, not denticulated, 

 and about two-thirds the length of the palra. At the base of 



Ann. i^ Mag. N, Hist. Ser.3. Fo/. xii. 2 



