Cover illustration. The axial complex of echinoderms is morphologically and functionally associated with the gonads and genital haemal ring, with the perihaemal coeloms and the oral haemal ring, with the intestinal vessels, with the perioral coelom, and with the nerve structures associated with the perihaemal coeloms and epineural canals. However, the axial complex of Crinoidea differs so dramatically from that of other echinoderms that the homology has been questioned. In this issue of the Journal of Morphology, Ezhova and Malakov (pp. 1456–1475) present a detailed microscopic anatomical analysis of the axial organ complex of crinoids and compare it with that of all other clades of echinoderms. The cover image shows a graphical reconstruction of the morphology of the axial organ of Himerometra robustipinna, perivisceral coeloms, intestine, and gonads (see Figure 1a of that paper for details).

(a) Goldfish fin blastema (bl); le, lepidotrichium; (b) newt limb blastema (bl) and wound epidermis (w); (c) regenerating lizard tail; (d) schematic gene network sustaining regeneration in fish and amphibians.

Workflow for acquisition of 3D model axis morphology (mid-head, midbody, mid-tail) and analysis. PGLS analysis did not show evidence for deviation from isometry in the head region of 12 Brachymeles species. This process was repeated for the midbody and mid-tail regions.

Most diagnostic characters to distinguish Salamandrina from the other European genera, as far as occipito-otic complex and vertebrae are concerned.

The ancestral sperm of the nematode order Rhabditida was reconstructed with maximum likelihood and Bayesian methods based on 44 ultrastructural sperm characters. The spermatogenesis of the “rhabditid” pattern appears to be relatively-well conserved.

Representation of the five phases which comprise the intra-puparial development of E. tenax (Diptera, Syrphidae). From left to right: prepupa, cryptocephalic pupa, phanerocephalic pupa, pharate adult, and imago. During the development of the pharate adult phase, the pupal cuticle that encapsulated the forming adult gets sclerotized over the head, a feature which had not been previously reported from other hoverflies.

Electron micrograph of lobules and acini of bulbourethral gland during the (a) early rainy and (b) dry seasons. L, lobules; BL, basal lamina; PC, principal cell; DC, dense cell; SV, secretory vesicles; M, mitochondria; RER, rough endoplasmic reticulum.

The microscopic anatomy of the axial complex and circumoral complex of the feather star Himerometra robustipinna is studied and compared with modern eleutherozoans and hemichordates.

The aim of the study was to histologically identify the vasa nervorum of epicardial nerves in porcine hearts. Vasa nervorum were present at 75.7% of these nerves. Similar blood vessels were much less frequently present in the vicinity of Purkinje fibers.

• The lacrimal/ectethmoid region of waterfowl carries substantial phylogenetic signal.
• Major “molecular” groups occupy distinct domains of a lacrimal phylomorphospace.
• Three main lacrimal morphotypes and two major evolutionary transitions are recognized.

Shark pectoral fins vary in gross morphology and skeletal anatomy across a spectrum, rather than the binary categories that are previously used to classify species. Variations in skeletal anatomy relate to ecomorphotypes based on body size, migratory behavior, and habitat use. We hypothesize that fins with limited skeletal extent may be more flexible and are observed in smaller bodied species that occupy complex environments, whereas fins with extensive skeletal extent may be more hydrodynamically efficient to benefit large bodied, pelagic species. Differences in skeletal extent are most notable at the trailing edge of the fin, and we hypothesize that limited skeletal support in the trailing edge may allow the unsupported edge to move independently as a spoiler, generating destabilizing forces and increasing maneuverability.