EEPOET ON THE STOMATOPODA. 
83 
ventral surface of tire basal joint of the uropocl is usually much longer than the outer, 
and is usually furnished with a tooth on its outer edge, and in the older specimens there 
are indications, underneath the cuticle, of spines on the inner edge of the dactylus of the 
raptorial claw. In his classical paper on the Metamorphosis of the Stomatopoda, Claus 
pointed out that there are so many features of resemblance between the Alima and the 
various forms of Erichthus that the larval nature of Alima cannot be doubted. Milne- 
Edwards and Dana had found it difficult to draw any line between the two genera ; the 
first-named writer placing in the genus all Erichtliidae in which the ocular segment is 
exposed, while Dana includes in it those forms in which the distance from the anterior edge 
of the carapace to the mouth is greater than the distance from the mouth to the posterior 
edge. Claus shows that neither of these features serves to discriminate between 
Alima and Erichthus in every case, and he figures and describes a larval type which is 
intermediate between the two, having the elongated flattened carapace and the exposed 
eyes, but the mouth well forward, and the thoracic region well covered by the carapace. 
For this intermediate larval type he proposes the name Alimerichthus. Claus was not 
able to connect any one of his Alimas with a specific adult, but he shows that they 
resemble the adults of the Squilla type very closely, and he correctly decides that 
they are the larvae of this type, although he erroneously believes that they belong to 
the Lysiosquilla branch, rather than to the true Squillae } He says there can be no 
doubt that we must seek their adult representatives in the Squilla-gvoup, and that the 
Alima larva, as distinguished from Erichthus , belongs exclusively to the genus 
Lysiosquilla , which is characterised, like the Alima larva, by the elongation and loose 
articulation of the abdomen. The lower members of the genus Squilla are loosely 
articulated, like the Lysiosquillas, and the hind body is about as long in the one genus 
as it is in the other, and there is therefore no reason for believing that any of these 
larvae are young Lysiosquillas, although later researches have shown that he is correct in 
his surmise that they pertain to the Squilla-gromy. 
In a paper which was published in 1879 2 I described a series of Alima larvae, which 
were procured in abundance in the Chesapeake Bay, a locality where Squilla empusa is 
common, while no other Stomatopod is known to occur there, and I therefore advanced 
the opinion that this larva, a young stage of which is shown in figs. 4 and 5 of 
PI. I., is a young Squilla. Three years before, Faxon reared from a similar but slightly 
more advanced larva, a young Squilla, which had the characteristics of the adult Squilla 
empusa, and although his results were not published until 1882 3 the proof that Alima 
is a young Squilla is due to him. It is of course possible that some species 
of Lysiosquilla may also pass through an Alima stage, but I shall show that, among 
^Metamorphose der Squilliden, p. 154. 2 On the larval stages of Squilla empusa. 
3 Selections from Embry ological Monographs compiled by Alexander Agassiz, Walter Faxon, and E. L. Mark-, 
I. Crustacea, Cambridge, 1882, Bull. Mus. Comp. Zool., vol. ix. No. I., pi. viii. figs. 2, 3. 
