QQ JOURNAL OF MARINE ZOOLOGY AND MICROSCOPY. 



first five bear gills — beautifully tufted or feathered, and kept con- 

 stantly in movement by the incessant paddling of the limbs where- 

 from they spring. No gills belong to the anterior part of the body ; 

 hence the carapace is small as it does not require to bend down 

 laterally to form gill chambers as in the Lobster: 



Good as the drawing given above, in life Squilla would scarcely 

 be recognised by it. No great seizing claws are visible, indeed none 

 of the maxillipeds are in evidence. I remember how, when I found 

 my first specimen, my heart sank very low — my capture was but a 

 sorry one — the great claws were gone ! And then as I little by little 

 examined more carefully, my spirits rose again — for there, snugly 

 folded up beneath the shelter of the projecting margins of the 

 carapace, were the two lost limbs, and equally safe were the other 

 foot jaws hidden closely away between the bases of the great claws. 

 A moment's thought will show how necessary it is for animals living 

 in a narrow burrow to have means of packing away, in small compass, 

 great limbs that are of no service except in procuring food, and which 

 otherwise would be getting in the way continually. In leisurely 

 swimming, the abdominal limbs — the swimmerets — are used as 

 paddles — but they by no means do all the work for the large oval 

 squame of each of the second antennse paddles assiduously and must 

 be of great assistance. 



The development is singularly interesting. Unlike the Deca- 

 pods, the Mantis Shrimps do not carry their spawn about till hatched, 

 attached to the swimmerets, but deposit it in their burrows in the 

 Zostera meadows — a great difficulty in the way of the study of the 

 embryology of this animal. 



Upon emerging from the egg, the larva is very simple in struc- 

 ture, soon assuming the form shown in PI. vi, Fig. 3. A great shield 

 covers nearly the whole of the body. In front, this carapace is drawn 

 out into a long spine or rostrum ; behind, into two other but smaller 

 spines, with a third tiny one midway between these two last. The 

 eyes are very large and show no trace of any stalked condition. 

 Indeed this sessile form characterises the early larval stage of all the 

 higher crustaceans when normal, and clearly points to an ancestry 

 with unstalked eyes. Two pairs of tiny antennse, two mandibles and 

 two pairs of maxillae are present, together with five powerful biramous 

 maxillipeds, co-equal in size — saving the second pair, which in their 

 slightly stouter form, forshadow the great clawed prehensile second 

 maxillipeds of the adult. 



The three succeeding somites of the thorax are clearly seen from 

 the first, but without sign of any appendages. In the very early 

 stage a large spinous-edged telson articulates with the hindmost of 



